User Guide IM/6517–6518 Rev. H

6517 and 6518Katharometer Units and Accessories for Non-Corrosive Sample Gases

The CompanyWe are an established world force in the design and manufacture of measurement products for industrial process control, flow measurement, gas and liquid analysis and environmental applications.

As a part of ABB, a world leader in process automation technology, we offer customers application expertise, service and support worldwide.

We are committed to teamwork, high quality manufacturing, advanced technology and unrivalled service and support.

The quality, accuracy and performance of the Company’s products result from over 100 years experience, combined with a continuous program of innovative design and development to incorporate the latest technology.

EN ISO 9001:2008

Cert. No. Q 05907

EN 29001 (ISO 9001)

Lenno, Italy – Cert. No. 9/90A

Stonehouse, U.K.

Electrical SafetyThis equipment complies with the requirements of CEI/IEC 61010-1:2010 'Safety Requirements for Electrical Equipment for Measurement, Control and Laboratory Use'. If the equipment is used in a manner NOT specified by the Company, the protection provided by the equipment may be impaired.

SymbolsOne or more of the following symbols may appear on the equipment labelling:

Warning – Refer to the manual for instructions Direct current supply only

Caution – Risk of electric shock Alternating current supply only

Protective earth (ground) terminal Both direct and alternating current supply

Earth (ground) terminalThe equipment is protected through double insulation

Information in this manual is intended only to assist our customers in the efficient operation of our equipment. Use of this manual for any other purpose is specifically prohibited and its contents are not to be reproduced in full or part without prior approval of the Technical Publications Department.

Health and Safety

To ensure that our products are safe and without risk to health, the following points must be noted:

1. The relevant sections of these instructions must be read carefully before proceeding.

2. Warning labels on containers and packages must be observed.

3. Installation, operation, maintenance and servicing must only be carried out by suitably trained personnel and in accordance with the information given.

4. Normal safety precautions must be taken to avoid the possibility of an accident occurring when operating in conditions of high pressure and/or temperature.

5. Chemicals must be stored away from heat, protected from temperature extremes and powders kept dry. Normal safe handling procedures must be used.

6. When disposing of chemicals ensure that no two chemicals are mixed.

Safety advice concerning the use of the equipment described in this manual or any relevant hazard data sheets (where applicable) may be obtained from the Company address on the back cover, together with servicing and spares information.

1

Section Page

1 INTRODUCTION .............................................................. 21.1 General ..................................................................... 21.2 The Katharometer ..................................................... 2

1.2.1 Principle of Operation ..................................... 21.2.2 Accuracy and Response Time ........................ 31.2.3 Zeroing and Calibration .................................. 4

1.3 Katharometer Types .................................................. 61.3.1 Basic Construction ......................................... 61.3.2 Direct Measurement Types ............................. 61.3.3 Differential Measurement Types ...................... 61.3.4 Thermally Lagged Types ................................. 61.3.5 Thermostatically Controlled Types .................. 61.3.6 Intrinsically Safe Katharometers ...................... 7

2 ANCILLARY EQUIPMENT ............................................... 82.1 General ..................................................................... 82.2 Power Supply Unit .................................................... 82.3 Sample Gas Pump .................................................... 8

3 GAS ANALYSIS PANEL ASSEMBLIES ........................... 93.1 General ..................................................................... 93.2 Assembly 006540 138/TL or 006540 138/TC .......... 93.3 Assembly 006540 184/TL or 006540 184/TC .......... 93.4 Assembly Fixing Details ............................................. 9

Section Page

4 INSTALLATION .............................................................. 124.1 General ................................................................... 124.2 Mounting the Katharometer .................................... 124.3 Pipe Connections .................................................... 124.4 Electrical Connections ............................................. 13

4.4.1 Non I.S. Systems ......................................... 134.4.2 I.S. Systems ................................................. 13

5 MAINTENANCE AND SERVICING ................................ 175.1 General ................................................................... 175.2 Sources Of Error In Readings .................................. 17

5.2.1 Pressure ....................................................... 175.2.2 Flow ............................................................. 175.2.3 Leaks ........................................................... 175.2.4 Vibration ....................................................... 175.2.5 Impurities ..................................................... 175.2.6 Sampling ...................................................... 175.2.7 Temperature Variations ................................. 175.2.8 Bridge Current ............................................. 17

5.3 Zero Adjustment ...................................................... 175.4 Sensitivity Adjustment ............................................. 185.5 Damaged Or Flooded Katharometer ....................... 185.6 Fault Finding............................................................ 19

6 SPARES ......................................................................... 206.1 The Katharometer Unit ............................................ 206.2 Drying Absorption Chamber .................................... 206.3 Gas Sample Pump .................................................. 20

CONTENTS

2

CHLORINESULPHUR DIOXIDE

ETHYLENEHYDROGEN SULPHIDE

CARBON DIOXIDENITROUS OXIDE

WATER VAPOURARGON

ETHANEAMMONIA

CARBON MONOXIDENITRIC OXIDEAIRNITROGENOXYGEN

METHANENEON

HELIUMHYDROGEN

300200 400100908070605040302010 500 600 400 1000900800(LOGARITHMICSCALE)

1 INTRODUCTION

1.1 GeneralThis manual covers the installation and servicing ofkatharometer units (thermal conductivity gas analysers) for usein non-corrosive sample gas applications, together withessential sampling and ancillary equipment. The manual isintended to be read in conjunction with appropriate instructionmanuals for:

1) The katharometer power supply unit

2) The read-out device (e.g. potentiometric recorder orindicator)

3) Any special instructional material appropriate to the gasanalysis panel/assembly as supplied (e.g. soot filter,dehumidifier, etc.)

Warning. It is essential that all relevant instructions arecarefully studied prior to the installation of katharometersystems in potentially hazardous areas (specifically thosesystems covered by certificates of intrinsic safety). If in anydoubt concerning these systems, please contact thesupplier before proceeding.

1.2 The KatharometerThis section describes features common to all katharometertypes, together with the principle of operation upon which themeasurement depends.

1.2.1 Principle of OperationThe katharometer is a nonspecific device which measures gasconcentrations in binary (and some complex) mixtures bymaking use of the difference in the thermal conductivity betweenthe sample and a reference gas. The measurement, beingcontinuous and automatic, is ideally suited for processmonitoring and control purposes. The universal nature of thekatharometer permits many hundreds of different gas rangesand mixtures to be measured in a wide variety of applications.

All gases and vapours have a characteristic thermal conductivitywhich is largely independent of pressure, and which variesconsiderably from one gas to another.

Fig 1.1 The Relative Thermal Conductivity of Some Common Gases,Shown on a Logarithmic Scale, Using Air (=100) as a Base.

3

R6

560

= Replaced by a resistor on two-filamentkatharometers.*

LocalSetZero

S1 E2

S2E1Span

R5IK

R4IKΩ

R8 (y)

R x

R7 (s)

9

10OptionalRemote Zero1kΩ

StabilisedPowerSupply

1+

4-

3

2

5

6

Output 2(Dual Range)

Direct measurement Differential measurement

Reaction= Remote zero operation only.= Dual range versions only.

Values for R7, R8 and Rx depend uponapplication.

E1

S1

E2

S2

E1

S1

E2

S2

R1IKΩ

R3560

*

* Output 1(Single Range)

Note. A 510Ω resistor is fitted acrossterminals 9 and 10 when remote zero is notfitted.

1 INTRODUCTION…

In a katharometer, this physical property is utilized by passing a carefully controlled direct current through a fine electrical conductorsurrounded by the sample gas. The temperature of the conductor rises, due to the current, until a state of thermal equilibrium isreached with the surrounding gas. When this condition exists the electrical energy supplied to the conductor is equal to the thermalenergy lost from it by heat transfer through conduction, convection and radiation. Provided that the last two of these losses can bereduced to a negligible minimum, the temperature of the conductor will depend only upon the heat transfer due to conduction throughthe gas. The electrical resistance of a conductor is dependent upon temperature and, by making a measurement of this resistance,a measurement is also made of the thermal conduction of the gas.

The katharometer consists of four (or two) very fine glass coatedplatinum wire filaments set in a metal block having a high thermalcapacity. The filaments are connected in a Wheatstone bridgearrangement (see Fig. 1.2) with one pair of opposite arms sealedin a reference gas and the remaining pair exposed to the samplegas. The gas can be pumped through the block or drawnthrough by an aspirator (unless supplied under positive pressureconditions); both methods ensuring a steady sample flow rate.The Wheatstone bridge is fed from a constant current supply,and differences in temperature between filament pairs cause anelectrical imbalance in the bridge which is a function of thedifference in thermal conductivity between the gases. Theelectrical imbalance of the bridge produces an output signalwhich can be indicated directly and calibrated in terms of thecomposition of the gas sample. For accurate readings, thecurrent supply to the Wheatstone bridge must be kept constant;a change of only 1% in current can cause approximately 3%change in bridge sensitivity.

1.2.2 Accuracy and Response TimeThe accuracy of measurements made using a katharometerdepends largely on the conditions under which it is used. Duringinitial calibration it is set to better than 1% f.s.d. Factors whichaffect the overall accuracy of the measurement when inoperation, are as follows:

1) The accuracy with which reference gases can be made oranalysed for calibration purposes.

2) The accuracy with which the sample gas can be analysed onsite, to provide information for calibration duringmanufacture of the katharometer.

3) The presence of impurities in the sample gas, e.g. watervapour.

4) The introduction into the sample of an additional gascomponent not foreseen in the original calibration.

5) Contamination of the sample to be analysed before reachingthe katharometer, e.g. by air leaks in the sampling pipework.

6) Incorrect katharometer supply current.

7) Large deviations of ambient temperature whilst using akatharometer without temperature compensation.

Fig. 1.2 Katharometer Internal Wiring

4

(Both measurements made at 100 ml min–1 flow rate)

12011010090807060504030201000

10

20

30

40

50

60

70

80

90

100 %

% C

HA

NG

E

20% CO2 IN AIR

10% H2 IN AIR

DEAD TIME

90% STEP CHANGE

100% STEP CHANGE

1 Sec

20 Sec

50 Sec

2.5 Sec

51 Sec

110 Sec

10%H2 IN AIR 20%CO2 IN AIR

TIME (Secs)

…1 INTRODUCTION

Fig. 1.3 shows speed of response curves for two gas mixtureswhich may be taken as typical. The curves are seen to beapproximately exponential with an initial delay (the dead time).Response time depends upon:

a) The geometry of the katharometer cell.

b) The diffusion rate of the gas.

c) The sample flow rate and the length of piping between thesampling point and the katharometer.

d) The thermal inertia of the katharometer filament.

1.2.3 Zeroing and CalibrationThe measurement zero of a katharometer analyser is determinedby the composition of the gas in its reference cells. This ischosen to have both a thermal conductivity and a temperaturecoefficient of thermal conductivity, as close as possible to thoseat one extreme concentration of the sample gas, thus ensuring asymmetrical bridge and reducing zero errors. The gas chosenmust be stable and must maintain these characteristics duringthe working life of the katharometer. An analyser zero is usuallyone which can be readily checked by reference to a gas which iseasily obtainable in a high state of purity.

The electrical zero of the bridge is set during manufacture, andan additional trimming adjustment is provided on the unit in theform of a potentiometer (the ‘zero adjustment’ control) – Figs 1.4and 1.5. This control may, if required, be remotely installed asshown in Fig. 1.2. The potentiometer value is chosen to ensurethat serious maladjustment of zero cannot occur.

The design of the katharometer is such that its sensitivityremains constant. Slight contamination of a filament can cause achange in zero, but the sensitivity will remain constant and thekatharometer may continue to be operated, until it is no longerpossible to compensate for the zero change within the range ofthe zero adjustment available.

More severe contamination will require the katharometer to becleaned.

Fig. 1.3 Katharometer Unit – Typical Response Curves

5

Thermistor(Model 006518 Only)

Stainless Steel Tubing

Katharometer Block

Sample Inlet

Power Transistor(Model 006518 Only)

Zero Adjustment

Insulation Sheet(Thermal lagging)

Terminal ConnectionBlock

Cable Gland

Protection Diodes(intrinsically Safe VersionsOnly)

Sample Outlet

NOTE Ignition arrestors may be fitted tosample inlet and outlet unions on someintrinsically safe versions.

123456789

101112

Thermistor(Model 006520 Only)

Stainless Steel Tubing

Katharometer Block

Sample Inlet

Power Transistor(Model 006520 Only)

Insulation Sheet(Thermal lagging)

Terminal ConnectionBlock

Cable Gland

Protection Diodes(intrinsically Safe VersionsOnly)

Sample Outlet

NOTE Ignition Arrestors may be fitted tosample inlet and outlet unions on someintrinsically safe versions.

123456789

101112

Zero Adjustment

1 INTRODUCTION…

Fig. 1.4 Direct Measurement Katharometers: Models 006517 & 006518 (non I.S.) – Models 006539960 & 006548001 (I.S.)

Fig. 1.5 Differential Measurement Katharometer: Models 006520 & 006521 (non I.S.) – Model 006539970 (I.S.)

6

…1 INTRODUCTION

1.3 Katharometer Types1.3.1 Basic ConstructionFigs 1.4 and 1.5 show the internal layouts of the seven basictypes of ABB katharometer unit, whilst Fig. 4.1 showsdimensions and fixing details.

The katharometer unit is mounted within a steel case fitted withfixing straps for wall mounting. Cable glands are provided forelectrical connections, together with sample gas inlet and outletconnectors appropriate to the type of measurement. The fourplatinum filaments comprising the bridge network are mountedin a plated solid brass block, and stainless steel tubing withplated brass connectors carry the sample gas to and from thisassembly. The katharometer block is mounted on four thermallyinsulating pillars, and the inside faces of the case are lined withexpanded polystyrene to provide thermal lagging. The lid of thecase is similarly insulated, except for the hole protected by asliding cover to enable adjustment of the ‘SET ZERO’potentiometer.

Fitted to the katharometer block is a circuit board on which ismounted a potentiometer having a slotted spindle aligned withthe hole in the case lid. This is the zero adjustment control.Clockwise rotation of this control shifts the analyser readingupscale, anticlockwise down scale.

The basic features described above are common to the fourbasic types of katharometer Unit, viz.

– direct measurement

Thermally lagged

– differential measurement

– direct measurement

Thermostatically controlled

– differential measurement

In the following sections the features specific to each type aredescribed in greater detail. Choice of katharometer type islargely influenced by the application, i.e. the nature of the gas tobe measured, its range, the ambient conditions, and thesampling arrangements. Although the katharometer principle isstrictly applicable to measurements on binary gas mixtures only(the ideal being two gases of widely differing thermalconductivity), its use can be extended by:

a) Exploiting a known relationship between two or moreconstituents of a multi-component mixture (e.g. the N2/02

ratio in air) to form a pseudo binary mixture.

b) Sample pretreatment, e.g. drying or saturating with watervapour.

c) Comparing the sample gas before and after a reaction (adifferential measurement).

1.3.2 Direct Measurement TypesThe direct measurement katharometer is the simplest and mostcommon type. The sample gas to be measured is delivered tothe exposed filaments, and is compared with a standard gassealed in the reference filaments of the katharometer bridge –see Fig. 1.2.

Direct measurement methods are suitable for dry sample gasesor for wet gases when:

a) the gas sealed in the reference filaments contains sufficientwater vapour to ensure 100% saturation and the sample gasis similarly fully saturated, or

b) the sample gas is passed through a desiccating agent suchas calcium chloride before entering the katharometer, or

c) the effect of water vapour is very small compared with theoutput from the katharometer bridge, e.g. 0-100% H2 in air –see Fig. 1.1.

1.3.3 Differential Measurement TypesIn a differential measurement katharometer all four filaments inthe katharometer block are exposed to the sample gas, but theflow of gas is so arranged that, after passing through the first pairof filaments, it undergoes a chemical reaction before enteringthe remaining pair of filaments – see Fig. 1.2. The two sides ofthe katharometer bridge thus pass the gas in differentconcentrations of the reacting constituent, and the resultingkatharometer reading is a measure of the concentration of thisconstituent in the sample gas.

1.3.4 Thermally Lagged TypesBoth direct and differential measurement katharometer typesare normally supplied thermally lagged, i.e. the case is lined withexpanded polystyrene to provide thermal insulation and hencetemperature stabilisation for the katharometer block.

The katharometer is designed to have a high thermal inertia sothat, during normal operation, no significant temperaturegradient occurs across the block. When exceptional stability isrequired, variations in zero due to ambient temperaturefluctuations can become significant. Temperature variations canalso cause errors in sensitivity and hence accuracy. The effectvaries considerably from one gas to another and to offset this thereference gas is chosen to have a conductivity and temperaturecoefficient of conductivity, as close as possible to that of thesample gas at the zero point.

If it is likely that ambient temperature variations will causeunacceptable errors, then a thermostatically controlledkatharometer must be used.

1.3.5 Thermostatically Controlled TypesThe thermostatically controlled katharometer, in addition tobeing thermally insulated, also contains a controlled heatingfacility to maintain a stable block temperature of approximately45°C (or 55°C) ± 0.5°C over an ambient temperature range of0°C to 40°C (or 0°C to 50°C).

7

1 INTRODUCTION

1.3.6 Intrinsically Safe KatharometersWhen monitoring flammable or potentially flammable gasmixtures, precautions are necessary to ensure that themonitoring equipment will not cause an explosion. For thispurpose, an intrinsically safe katharometer and associatedequipment is supplied which limits the amount of electricalpower appearing in the hazardous area to a level insufficient toignite the flammable gas, even under a double fault condition.

Intrinsically safe katharometers require a power supply which isregulated to supply the constant current required, yet withinsufficient energy to cause ignition if a fault condition shouldoccur. The power supply unit, which must only be of the type4234 500/501 must be mounted in a safe area and speciallimitations are imposed on the parameters of the interconnectingcables.

The installation of intrinsically safe instrumentation is controlledby strict regulations and standards. Full details are qiven in theOperating Instructions for the Intrinsically Safe Power SupplyUnit (Model 4234 500/501). ABB katharometer units for use inhazardous areas are designed to meet the requirements of ATEXDIRECTIVE 94/9/EC to code Ex ia IIC T4 Ga. These are panelmounted katharometers and are designated type 006539960/Kor /J for direct and type 006539970/K or /J for differentialmeasurements. They are covered by certificate No. BAS01ATEX 1042. A further certificate of intrinsic safety BAS No. EX01E2044, covers the use of katharometer systemsincorporating these units under approved conditions. Particularcare must be taken when installing the equipment and allconditions specified in the certification schedule must be strictlycomplied with. If in any doubt, it is essential to contact thesuppliers before proceeding.

The principle modification to the katharometer unit forintrinsically safe operation is the addition of a pair of zenerdiodes, mounted on a heat sink within the katharometer housingand connected in parallel across the supply input to theWheatstone bridge. The function of these diodes is to limit themaximum voltage capable of being developed across the bridgeunder fault conditions, to a level which provides insufficientpower to cause ignition of a flammable gas sample in contactwith the heated filaments. Sintered metal flame arrestors may beincorporated into the inlet and outlet unions of the katharometeras an additional safeguard although these are not required underthe I.S. certification.

Temperature controlled katharometer types cannot be used inhazardous areas (whether differential or direct measuring), sincethe operating currents used to supply temperature controlcircuits are potentially hazardous in a flammable environment.Similarly, and for this reason, furnace elements and most electricpumps must be excluded from operating in the hazardous area.

8

4 Mounting Slots in Feet6 wide by 10 long

Ta A.C. Supply (Single Phase)Leads 230 long

ø8

19

All dimensions in mm

25

143

73

92140

48

2 ANCILLARY EQUIPMENT

2.3 Sample Gas PumpIn some applications, the sample gas is pumped through thekatharometer unit by a small electric pump, fitted with a filter andsilencer. A diaphragm pump is normally supplied for this purposewith a motor suitable for a standard single phase a.c. supply.This pump will aspirate approximately 1 l min–1 of sample gas.

The pump and its filter and silencer are fitted with stems suitablefor connection by means of 6 mm i.d. push-on tubing.

The pump may be mounted in any position in which the motorshaft axis is horizontal. Fixing is by four feet having slotted holessuitable for M4 screws on fixing centres 73 mm x 48 mm. Thepump weighs approximately 2 kg and must be protected by a1 A fuse in its supply leads.

Fig. 2.1 Sample Gas Pump (Model 2370 003 – 230 V version or 2370 004 – 115 V version)

2.1 GeneralFor the katharometer unit to function correctly, the sample gasmust often be suitably conditioned before passing through it.This section describes various ancillary items which providesample conditioning. Each application will include some of theseitems connected in the sample line, either mounted together ona panel with the katharometer, or as separate items pipedtogether with stainless steel tubing.

2.2 Power Supply UnitThe katharometer unit is powered from a separately mountedpower supply unit, which is essentially a highly stable constantcurrent source for the katharometer bridge. The working currentis normally 350 mA. In some applications, however, it isnecessary to operate with the katharometer filaments at a lowertemperature than normal to prevent thermal dissociation of thesample constituents: a lower working current, usually 250 mA, isthen used. Where sensitivity of certain applications (non I.S.) islow, the katharometer output can be increased by operating at abridge current of 500 mA.

The type of power supply units are as follows:

Model Function4234 500/501 Intrinsically safe supply for a single

katharometer unit only (230/115 V)

4234 600/601 Low energy bridge supply unit for a singlekatharometer unit only.

Bridge supply and unstabilised heater supplyfor one thermostatically controlledkatharometer unit.

9

ylbmessA

LT/831045600 CT/831045600

retemorahtaK 715600 815600

eguaGwolF 044525600 044525600

evlaVeldeeN 084525600 084525600

rebmahCgniyrD 006525600 006525600

ylbmessA

LT/481045600 CT/481045600

retemorahtaK 715600 815600

eguaGwolF 044525600 044525600

evlaVeldeeN 084525600 084525600

rebmahCgniyrD 006525600 006525600

pmuPcirtcelE 400/3000732 400/3000732

rebmuNylbmessA CT&LT/831045600 CT&LT/481045600 K/&J/302045600 000845600

mmnisnoisnemidllA

snoisnemidlenaP)tsrifsnoisnemidlatnoziroh(

503x016 016x503 503x016 503x016

sertnecgnixiF)tsrifsnoisnemidlatnoziroh(

762x275 275x762 762x275 762x275

)seloh4(retemaidelohgnixiF 5.9 5.01 5.01 5.01

llawmorfnoitcejorP 251 302 302 302

epip.d.orofgnittifepiptelnIretemaid

8 8 8 6

epip.d.orofgnittifepipteltuOretemaid

8 8 8 6

:etoN.rebmahcgniyrdTUOHTIWtubLT/831045600saLT/731045600.rebmahcgniyrdTUOHTIWtubCT/831045600saCT/731045600

3 GAS ANALYSIS PANEL ASSEMBLIES

3.1 GeneralMost applications for gas analysis will include at least someitems of ancillary equipment, and these items may beconveniently grouped together on a panel assembly mounted ona wall adjacent to the sampling point. It is then only necessary tomake the appropriate electrical and piping connections to thepanel.

Many different combinations and configurations are possible,but experience has shown that the majority of applications canbe met from a limited number of basic assemblies, all involvinguse of a katharometer unit. A full list of these standardassemblies, together with dimensional details, may be obtainedfrom ABB.

The two most commonly occurring assemblies for non-corrosive sample gas measurements are described here.

3.2 Assembly 006540 138/TL or 006540 138/TCThe assembly is intended for a clean, wet gas at a pressureabove 5 in. water gauge, and uses a direct measurementkatharometer.

Assemblies comprise:

3.3 Assembly 006540 184/TL or 006540 184/TCSamples which may be measured by this assembly must beclean, wet or dry, and at a pressure between –l0 in. and +5 in.water gauge; a direct measurement katharometer is used. Thisassembly must not be used for intrinsically safe applications.

Assemblies comprise:

3.4 Assembly Fixing DetailsSee Table 3.1. Panel assembly drawings for low and highpressure versions are shown ing Figs 3.1 and 3.2 respectively.

Table 3.1 Assembly Dimensions

10

Electricalinterconnections

Flow gauge

Gas sampleoutlet

Local zeroadjustment

Drying chamber

Katharometerunit case

Meteringvalve

Gassample

inlet

Electricalinterconnections

Flow gauge

Gas sampleoutlet

Local zeroadjustment

Drying chamber

Katharometerunit case

Meteringvalve

Gassample

inlet

…3 GAS ANALYSIS PANEL ASSEMBLIES

Fig. 3.1 006540 203/J & /K and 006540 138 & 137 TL and TC Options Low Pressure Katharometer System

Fig. 3.2 006548 000 High Pressure Katharometer System

11

Terminal Block

Flow gauge

Local zeroadjustment

Drying chamber

Katharometerunit case

Meteringvalve

Gas sample inletL

N E

MA

INS

Gas sample outletTee Blocks

Pump

Filter

Silencer

3 GAS ANALYSIS PANEL ASSEMBLIES

Fig. 3.3 006540 184 TL and TC Versions

12

24m

m

103m

m

109mm 238mm

178mmFixing Centres

21mm

25mm

Four Fixing Holes 7mm Dia25mm 57mm

A B

80mm

178m

mFi

xing

Cen

tres

22m

m

152m

m

25mm53mm

A B

*

Thermally LaggedThermostatically ControlledIntrinsically Safe(Thermally Lagged Only)

Katharometer TypesDirect006517006518

006539 960J or K

Differential006521006520

006539 970J or K

This Dimension Increased to 45mmif flame arrestors fitted.All Couplings For 4mm o.d. PipesCoupling'A' For Direct Measurements TypesCouplings 'A' & 'B' For Differential Measurements Types

*

Cable Gland Suitable For Cables6.5-10.5mm Dia.

Intrinsically Safe(High Pressure 10 bar)

006548 001

162m

m

4 INSTALLATION

4.1 GeneralThis section relates principally to the katharometer unit,installation details for the ancillary items being given wherenecessary under their appropriate heading in Section 2. Where akatharometer unit is mounted as part of a standard panelassembly, the following relates to the panel as a whole.

4.2 Mounting the KatharometerFig. 4.1 shows the dimensions and fixing details for the eightbasic types of katharometer unit. The case has overalldimensions of 233 mm x 157 mm x 109 mm and four fixingholes are located in straps welded to the back of the case. Thesefixing holes are suitable for bolts up to 7 mm diameter, and arelocated on centres 178 mm x 178 mm.

Install the katharometer unit with its lid in the vertical plane in aposition which allows adequate access to terminal connectionsand controls. The unit can tolerate up to approximately 20° ofinclination from the upright position without adverse effect. Thesite must be clean and dry, reasonably well illuminated and freefrom extreme levels of vibration. The installation should not besubject to draughts, heat radiation or strong direct sunlight.Large fluctuations of ambient temperature must be avoidedunless a thermostatically controlled katharometer is used.Although the katharometer is robust, care must be taken toavoid accidental damage during installation (and, in the case ofa panel assembly, to any glass components on the panel).

Keep the distance between the sampling point and thekatharometer as short as possible to minimise time lag due tolong pipe runs. The time lag incurred in such runs can besignificant if, for instance, the katharometer is supplying a signalto a process control system.

The katharometer unit pipe connections are as shown inFig. 4.1. The pipe couplings (two for direct measurement andfour for differential measurement) are suitable for 4 mm o.d.tubing. Care must be taken in assembling the couplings on tothe tubing to ensure freedom from leaks.

4.3 Pipe ConnectionsThe standard pipe connectors fitted to a panel assembly aresuitable for 8 mm o.d. tubing, (or 6 mm o.d. tubing for006548 000).

Choice of material for the sample line, and its method ofinstallation, are important. The following points are given forguidance.

1) The sample line material must not

a) react chemically with the sample gas.

b) be permeable to the sample constituents or thesurrounding atmosphere.

Most plastics and rubber tubing therefore are unsuitable.Short lengths of neoprene or nylon tubing may, however, beused to butt-joint two pipes of material.

2) For dry sample gases the sample line must neither bepermeable to, nor absorb, water vapour.

3) If the sample gas has a dew point above ambienttemperature, the sample line must be installed with adownward gradient to a water trap fitted at the input to thekatharometer unit. The gradient should be not less than30 mm per metre. If this is not possible, water traps must befitted at each trough.

Fig. 4.1 Katharometer Unit Dimensions and installation Details

13

12

11

10

9

8

7

6

5

4

3

2

1

-ve

+ve

-ve

+ve

-ve

+ve

Allocated for special purposes as required

Provision for external zero control(1k0 variable resistor) – see also Fig. 1.2

Power supply to temperature control circuit(Models 006518 & 006520 only)

Bridge output (Range 2)

Power supply (-ve) 350 mA

Bridge output (Range 1)

Power supply (+ve) 350 mA

NoteTerminals 2 and 5 are common.

4 INSTALLATION…

4) When sampling products of combustion, copper tubingmust not be used as it will corrode – the sample gas is oftencooled in passing from a soot filter/sampling point andconsiderable condensation can be produced. Thiscondensation is acidic and must not be allowed to drain intothe katharometer.

5) The most widely used material is 316 type stainless steel.Pipes should have an external diameter of 6 mm or 8 mm, asappropriate, and a wall thickness sufficient to withstand themaximum pressure encountered at the sampling point.

6) If the gas contains solid particles it must be filtered beforeentering the sample lines. If there is only a minimal dustcontent, a filter can be fitted at the input to the katharometerunit. Such a filter is often advisable as an extra precaution forpre-filtered dusty gases.

4.4 Electrical Connections – Figs 4.2 to 4.64.4.1 Non I.S. SystemsAll electrical cables to the katharometer unit must enter via the20 mm cable glands on the right hand side of the unit casing –see Fig. 4.1. These glands are suitable for cables 6.5to 10.5 mm diameter.

Connections must be made to the numbered 12-way screwterminal block mounted to the right hand side of the circuit boardinside the case.

Remove the case lid after releasing its four fixing screws andmake the connections shown in Fig. 4.2.

When installing cables observe the following:

1) The (loop) lead resistance of the cable from the power supplyunit to the katharometer bridge (i.e. the 350 mA currentsupply) must be limited to 4 Ω total per katharometer unlessotherwise stated in the power supply unit instruction manual.Additional katharometers must be connected in series (Pins1 and 4) across the power supply unit output terminals.Further details may be found in the instruction manual for thepower supply unit.

2) Where several katharometer with temperature controlcircuits are to be installed, a separate Type 4234 600/601power supply unit must be provided for each katharometerand connections made in accordance with the handbook forthat unit.

3) Screened cables should be used to connect thekatharometer to a remote potentiometric indicating device:these cables should not be installed in the same cable run asany a.c. supply cables in order to minimise the risk ofinterference.

4) On dual range katharometers, the second signal output isfrom terminals 5 and 6; terminals 2 and 5 being common toboth outputs. The range of measurement giving the greaterchange in thermal conductivity will always be connected toterminals 5 and 6. See Figs 1.1 and 1.2 for clarification.

5) When the katharometer is used with an external zero controlinstead of the zero adjustment fitted within the unit, connectthe remote zero control (1k0 variable resistor) as shown inFig. 1.2, so that clockwise rotation of the spindle producesan upscale adjustment of the katharometer zero. If thekatharometer has been supplied for remote zero adjustment,remove the 510 Ω resistor from terminals 9 and 10 andreplace by the remote 1k0 variable resistor before zeroingthe katharometer.

4.4.2 I.S. SystemsFor katharometer units which are located in hazardousenvironments, special attention must be given to the electricalconnections between the safe and hazardous areas of theinstallation. The choice of cable connecting the power supplyunit to the katharometer is strictly limited by the requirement fora low inductance/resistance ratio. The katharometer bridgeoutput signal must be connected to indicating devices in thesafe area only via approved zener safety barriers. Full details ofthese requirements, together with installation details, are given inFigs 4.3, 4.4 & 4.5. and the instruction manuals for the particularsystem or its associated equipment (Purge Gas Monitor type6553 and/or power supply unit type 4234 500/501 for example).

Warning. It is essential that these manuals are consultedbefore commencing installation.

Fig. 4.2 Katharometer Terminal Block Electrical Connections

14

Saf

e A

rea

See

Not

e 9

See Note 1

Not

e 1

App

arat

us w

hich

is u

nspe

cifie

d ex

cept

that

it m

ust n

ot b

e su

pplie

d fro

m n

or c

onta

in in

nor

mal

or a

bnor

mal

con

ditio

ns a

sou

rce

of p

oten

tial w

ith re

spec

t to

eart

h in

exc

ess

of 2

50 v

olts

r.m

.sor

250

vol

ts d

.c.

Not

e 2a

The

capa

cita

nce

and

eith

er th

e in

duct

ance

or

the

indu

ctan

ce to

resi

stan

ce (L

/R) r

atio

of t

heca

ble

conn

ecte

d be

twee

n th

e +

and

– te

rmin

als

of th

e po

wer

sup

ply

Type

423

4500

/501

and

term

inal

s 1

and

4 o

f a k

atha

rom

eter

Typ

e 00

65XX

mus

t not

exc

eed

the

follo

win

g va

lues

:

Haz

ard

ous

Are

a

See

Not

es 2

& 3

for

cabl

e de

tails

23

14

23

14

23

14

TB5

1817

TB6 19 20

PO

WE

R S

UP

PLY

TYP

E 4

234

500/

501

CE

RTI

FIE

D [E

x ia

Ga]

IIC

(–20

°C≤

Ta ≤

+55

°C)

CE

RTI

FIC

ATE

No

BA

S 0

1 AT

EX

7041

- +

21 3 21 3RS

1

RS

2

B1

B2

B3

Gas

Mo

nito

r T

ype

6553

– +

Indi

cato

reg

468

9

I1

– +

Indi

cato

reg

468

9

I2

4 –

1+ 9 10 3 –

2+

KAT

HA

RO

ME

TER

TYP

E 0

065X

XX

CE

RTI

FIE

D E

x ia

IIC

T4

Ga

CE

RTI

FIC

ATE

No

BA

S 0

1 AT

EX

1042

3 –

2+ 10 4 –

1+6 –

9

KAT

HA

RO

ME

TER

TYP

E 0

065X

XX

CE

RTI

FIE

D E

x ia

IIC

T4

Ga

(–20

ºC ≤

Ta

≤ +

55ºC

)

(–20

ºC ≤

Ta

≤ +

55ºC

)

CE

RTI

FIC

ATE

No

BA

S 0

1 AT

EX

1042

Junc

tion

boxe

s (if

requ

ired)

see

not

e 6.

Loca

tion:

Haz

ardo

us A

rea

or S

afe

Are

a

See

Not

e 1

See

Not

e 1

Junc

tion

boxe

s (if

requ

ired)

see

not

e 6.

Loca

tion:

Haz

ardo

us o

r S

afe

Are

a

RV

1

RV

2

Gro

upC

apac

itanc

ein

μF

Indu

ctan

cein

mH

L/R

rat

ioin

μH

/Ohm

IIC IIB IIA

7.63

113

999

0.05

0.14

0.37

22 88 177

or

Gro

upC

apac

itanc

ein

μF

Indu

ctan

cein

mH

L/R

rat

ioin

μH

/Ohm

IIC IIB IIA

38 999

999

0.40

1.20

3.20

75 225

600

or

Gro

upC

apac

itanc

ein

μF

Indu

ctan

cein

mH

L/R

rat

ioin

μH

/Ohm

IIC IIB IIA

40 999

999

0.05

0.16

0.43

52 210

421

or

Gro

upC

apac

itanc

ein

μF

Indu

ctan

cein

mH

L/R

rat

ioin

μH

/Ohm

IIC IIB IIA

40 999

999

0.37

1.37

3.28

79 316

632

or

Not

e 2b

The

capa

cita

nce

and

eith

er th

e in

duct

ance

or

the

indu

ctan

ce to

resi

stan

ce (L

/R) r

atio

of t

he c

able

sco

nnec

ted

betw

een

(a) t

erm

inal

s 17

& 1

8 of

the

gas

mon

itor

type

665

3 an

d te

rmin

als

9 &

10

of a

kat

haro

met

er T

ype

0065

XX, (

b) te

rmin

als

19 &

20

of t

he d

ispl

ay/c

ontr

ol u

nit a

nd te

rmin

als

9 &

10

of a

kat

haro

met

er T

ype

0065

XX.

Not

e 2c

The

capa

cita

nce

and

eith

er th

e in

duct

ance

or

the

indu

ctan

ce to

resi

stan

ce (L

/R) r

atio

of t

he c

able

sco

nnec

ted

betw

een

3 &

4 o

f bar

rier

B2

plus

term

inal

4 o

f bar

rier

B3

of g

as m

onito

r ty

pe 6

653

and

term

inal

s 2,

3 &

6 o

f a k

atha

rom

eter

Typ

e 00

65XX

, mus

t not

exc

eed

the

follo

win

g va

lues

:

See

Not

es 2

& 3

for

cabl

e de

tails

Circ

uit A

Circ

uit B

(see

Not

e 8)

Not

e 3

The

cabl

e m

ay b

e se

para

te c

able

s or

may

be

inst

alle

d as

sep

arat

e ci

r

Not

e 2d

The

capa

cita

nce

and

eith

er th

e in

duct

ance

or

the

indu

ctan

ce to

res

ista

nce

(L/R

) rat

io o

f the

cab

les

conn

ecte

dbe

twee

n te

rmin

als

3 &

4 o

f bar

rier

B1

of g

as m

onito

r ty

pe 6

553

and

term

inal

s 2

& 3

of K

atha

rom

eter

type

006

5XX,

m

ust n

ot e

xcee

d th

e fo

llow

ing

valu

es:

cuits

with

in a

type

‘A’ o

r a

type

‘B’

mul

ticor

e ca

ble

as d

efin

ed in

EN

6007

9 -

14: 2

008,

12.

2.28

(lat

est e

ditio

n) s

ubje

ct to

the

follo

win

g:a.

Eac

h ci

rcui

t sha

ll be

indi

vidu

ally

scr

eene

d w

ithin

a ty

pe ‘A

’ mul

ticor

e ca

ble.

b.Th

e pe

ak v

olta

ge o

f any

oth

er c

ircui

t with

in a

type

‘B’ m

ultic

ore

cabl

e m

ust n

ot e

xcee

d 60

vol

ts.

Not

e 4

The

inst

alla

tion

mus

t com

ply

with

nat

iona

l req

uire

men

ts (e

.g. i

n th

e U

K E

N60

079-

14: (

late

st e

ditio

n))

.N

ote

5Th

e sy

stem

mus

t be

mar

ked

with

a d

urab

le la

bel.

The

labe

l sho

uld

appe

ar o

n or

adj

acen

t to

the

prin

cipa

lite

m o

f ele

ctric

al a

ppar

atus

in th

e sy

stem

or

at th

e in

terfa

ce b

etw

een

the

intr

insi

cally

saf

e an

d no

n-in

trin

sica

lly s

afe

circ

uits

.Th

is m

arki

ng s

hall

incl

ude

the

wor

d S

YS

T or

SY

STE

M, e

.g.

‘BA

S S

YS

TEM

No

Ex

01E

2044

’ or

‘BA

S N

o E

x 01

E20

44 S

YS

T’N

ote

6A

junc

tion

box,

if u

sed,

mus

t sat

isfy

the

requ

irem

ents

of C

laus

es 6

.1 a

nd 6

.3.1

of E

N60

079:

11 (l

ates

t edi

tion)

.N

ote

7C

ircui

t A o

r C

ircui

t B m

ay b

e om

itted

.N

ote

8C

ircui

t B m

ay b

e id

entic

al to

Circ

uit A

.N

ote

9Th

is it

em m

ay o

r m

ay n

ot b

e fit

ted.

PO

WE

R S

UP

PLY

TYP

E 4

234

500/

501

CE

RTI

FIE

D [E

x ia

Ga]

IIC

(–20

°C≤

Ta ≤

+55

°C)

CE

RTI

FIC

ATE

No

BA

S 0

1 AT

EX

7041

- +

See

Not

e 10

Not

e 10

Zene

r bar

riers

(B1,

B2

& B

3) M

TL 7

755a

c B

AS

01

ATE

X 72

17 &

IEC

Ex B

AS

04.

0025

.

Dis

play

/Con

trol

Uni

tM

odel

655

3C

ER

TIFI

ED

[Ex

ia G

a] II

C(–

20ºC

≤ T

a ≤

+40

ºC)

CE

RT

No

BA

S 0

1 A

TEX

7043

& IE

CE

x B

AS

04.

0025

2a

2b

2d 2c

2b

2a

…4 INSTALLATION

Fig

. 4.3

Sys

tem

Dia

gra

m

15

4 INSTALLATION…

Fig

. 4.4

PS

U in

Ass

oci

atio

n w

ith

a K

atha

r om

eter

and

Oth

er S

afe

Are

a A

pp

arat

us w

ith

One

Zen

er D

iod

e B

arri

er

Not

e 1

App

arat

us w

hich

is u

nspe

cifie

d ex

cept

that

it m

ust n

ot b

e su

pplie

d fro

m n

or c

onta

in in

nor

mal

or a

bnor

mal

con

ditio

ns a

sou

rce

of p

oten

tial w

ith re

spec

t to

eart

h in

exc

ess

of 2

50 v

olts

r.m

.sor

250

vol

ts d

.c.

Not

e 2a

The

capa

cita

nce

and

eith

er th

e in

duct

ance

or

the

indu

ctan

ce to

resi

stan

ce (L

/R) r

atio

of t

heca

ble

conn

ecte

d be

twee

n th

e +

and

– te

rmin

als

of th

e po

wer

sup

ply

Type

423

4500

/501

and

term

inal

s 1

and

4 o

f a k

atha

rom

eter

Typ

e 00

65XX

mus

t not

exc

eed

the

follo

win

g va

lues

:

Gro

upC

apac

itanc

ein

μF

Indu

ctan

cein

mH

L/R

rat

ioin

μH

/Ohm

IIC IIB IIA

7.63

113

999

0.05

0.14

0.37

22 88 177

or

Gro

upC

apac

itanc

ein

μF

Indu

ctan

cein

mH

L/R

rat

ioin

μH

/Ohm

IIC IIB IIA

40 999

999

0.37

1.37

3.25

79 316

632

or

Not

e 2c

The

capa

cita

nce

and

eith

er th

e in

duct

ance

or

the

indu

ctan

ce to

resi

stan

ce (L

/R) r

atio

of t

he c

able

conn

ecte

d be

twee

n te

rmin

als

3 &

4 o

f MTL

775

5ac

zene

r di

ode

safe

ty b

arrie

r an

d te

rmin

als

2 &

3 o

f a k

atha

rom

eter

Typ

e 00

65XX

, mus

t not

exc

eed

the

follo

win

g va

lues

:

Not

e 3

The

cabl

e m

ay b

e se

para

te c

able

s or

may

be

inst

alle

d as

sep

arat

e ci

rcui

ts w

ithin

a ty

pe ‘A

’ or

a ty

pe ‘B

’m

ultic

ore

cabl

e as

def

ined

in E

N60

079

- 14

: 201

4, 1

2.2.

28 (l

ates

t edi

tion)

sub

ject

to th

e fo

llow

ing:

a.E

ach

circ

uit s

hall

be in

divi

dual

ly s

cree

ned

with

in a

type

‘A’ m

ultic

ore

cabl

e.b.

The

peak

vol

tage

of a

ny o

ther

circ

uit w

ithin

a ty

pe ‘B

’ mul

ticor

e ca

ble

mus

t not

exc

eed

60 v

olts

.

Not

e 4

The

inst

alla

tion

mus

t com

ply

with

nat

iona

l req

uire

men

ts

Not

e 5

The

syst

em m

ust b

e m

arke

d w

ith a

dur

able

labe

l. Th

e la

bel s

houl

d ap

pear

on

or a

djac

ent t

o th

e pr

inci

pal

item

of e

lect

rical

app

arat

us in

the

syst

em o

r at

the

inte

rface

be

intr

insi

cally

saf

e ci

rcui

ts.

This

mar

king

sha

ll in

clud

e th

e w

ord

SY

ST

or S

YS

TEM

, e.g

.‘B

AS

SY

STE

M N

o E

x 01

E20

44’ o

r ‘B

AS

No

Ex

01E

2044

SY

ST’

Not

e 6

A ju

nctio

n bo

x, if

use

d, m

ust s

atis

fy th

e re

quire

men

ts o

f Cla

uses

6.1

and

6.3

.1 o

f EN

6007

9:11

(lat

est e

ditio

n).

Saf

e A

rea

If R

equi

red

Saf

e A

rea

App

arat

usS

ee N

ote

1

Zene

r D

iode

Saf

ety

Bar

rier:

MTL

775

5ac

CE

RT

No

BA

S 0

1 A

TEX

7217

IEC

Ex

BA

S 0

4.00

25

Haz

ard

ous

Are

a

23

14

TB5

1817

PO

WE

R S

UP

PLY

TYP

E 4

234

500/

501

CE

RTI

FIE

D [E

x ia

Ga]

IIC

(–20

°C≤

Ta ≤

+55

°C)

CE

RTI

FIC

ATE

No

BA

S 0

1 AT

EX

7041

- +

21 3RS

1

– +

4 –

1+ 9 10 3 –

2+

KAT

HA

RO

ME

TER

TYP

E 0

065X

XX

CE

RTI

FIE

D E

x ia

IIC

T4

Ga

CE

RTI

FIC

ATE

No

BA

S 0

1 AT

EX

1042

(–20

ºC ≤

Ta

≤ +

55ºC

)

See

Not

e 1

Junc

tion

boxe

s (if

requ

ired)

see

not

e 6.

Loca

tion:

Haz

ardo

us o

r S

afe

Are

a

RV

1

See

Not

es 2

& 3

for

cabl

e de

tails

Dis

play

/Con

trol

Uni

tM

odel

655

3C

ER

TIFI

ED

[Ex

ia G

a] II

C(–

20ºC

≤ T

a ≤

+40

ºC)

CE

RT

No

BA

S 0

1 A

TEX

7043

& IE

CE

x B

AS

04.

0025

2a

2b

2c

I.S. E

arth

Gro

upC

apac

itanc

ein

μF

Indu

ctan

cein

mH

L/R

rat

ioin

μH

/Ohm

IIC IIB IIA

38 999

999

0.40

1.20

3.20

75 225

600

or

Not

e 2b

The

capa

cita

nce

and

eith

er th

e in

duct

ance

or

the

indu

ctan

ce to

resi

stan

ce (L

/R) r

atio

of t

he c

able

sco

nnec

ted

betw

een

(a) t

erm

inal

s 17

& 1

8 of

the

gas

mon

itor

type

655

3 an

d te

rmin

als

9 &

10

of a

kat

haro

met

er T

ype

0065

XX.

(e.g

. with

in th

e U

K th

e st

anda

rd E

N60

079-

14: (

late

st e

ditio

n) is

use

d).

16

Saf

e A

rea

Not

e 1

App

arat

us w

hich

is u

nspe

cifie

d ex

cept

that

it m

ust n

ot b

e su

pplie

d fro

m n

or c

onta

in in

nor

mal

or a

bnor

mal

con

ditio

ns a

sou

rce

of p

oten

tial w

ith re

spec

t to

eart

h in

exc

ess

of 2

50 v

olts

RM

Sor

250

vol

ts D

CN

ote

2aTh

e ca

paci

tanc

e an

d ei

ther

the

indu

ctan

ce o

r th

e in

duct

ance

to re

sist

ance

(L/R

) rat

io o

f the

cabl

e co

nnec

ted

betw

een

the

+ a

nd –

term

inal

s of

the

pow

er s

uppl

y Ty

pe 4

2345

00/5

01 a

ndte

rmin

als

1 a

nd 4

of a

kat

haro

met

er T

ype

0065

XX m

ust n

ot e

xcee

d th

e fo

llow

ing

valu

es:

Haz

ard

ous

Are

a

See

Not

e 1

Junc

tion

boxe

s (if

requ

ired)

see

not

e 6.

Loca

tion:

Haz

ardo

us o

r S

afe

Are

a

Gro

upC

apac

itanc

ein

μF

Indu

ctan

cein

mH

L/R

rat

ioin

μH

/Ohm

IIC IIB IIA

7.63

113

999

0.05

0.14

0.37

22 88 177

or

Gro

upC

apac

itanc

ein

μF

Indu

ctan

cein

mH

L/R

rat

ioin

μH

/Ohm

IIC IIB IIA

40 999

999

0.05

0.16

0.43

52 210

421

or

See

Not

es 2

& 3

2a 2b

Not

e 3

The

cabl

e m

ay b

e se

para

te c

able

s or

may

be

inst

alle

d as

sep

arat

e ci

rcui

ts w

ithin

a ty

pe ‘A

’ or

a ty

pe ‘B

’m

ultic

ore

cabl

e as

def

ined

in E

N60

079

- 14

: 200

8, 1

2.2.

28 (l

ates

t edi

tion)

sub

ject

to th

e fo

llow

ing:

a.E

ach

circ

uit s

hall

be in

divi

dual

ly s

cree

ned

with

in a

type

‘A’ m

ultic

ore

cabl

e.b.

The

peak

vol

tage

of a

ny o

ther

circ

uit w

ithin

a ty

pe ‘B

’ mul

ticor

e ca

ble

mus

t not

exc

eed

60 v

olts

.

Not

e 4

The

inst

alla

tion

mus

t com

ply

with

nat

iona

l req

uire

men

ts (e

.g. i

n th

e U

K E

N60

079-

14: (

late

st e

ditio

n)).

Not

e 5

The

syst

em m

ust b

e m

arke

d w

ith a

dur

able

labe

l. Th

e la

bel s

houl

d ap

pear

on

or a

djac

ent t

o th

e pr

inci

pal

item

of e

lect

rical

app

arat

us in

the

syst

em o

r at

the

inte

rface

bet

wee

n th

e in

trin

sica

lly s

afe

and

non-

intr

insi

cally

saf

e ci

rcui

ts.

This

mar

king

sha

ll in

clud

e th

e w

ord

SY

ST

or S

YS

TEM

, e.g

.‘B

AS

SY

STE

M N

o E

x 01

E20

44’ o

r ‘B

AS

No

Ex

01E

2044

SY

ST’

Not

e 6

A ju

nctio

n bo

x, if

use

d, m

ust s

atis

fy th

e re

quire

men

ts o

f Cla

uses

6.1

and

6.3

.1 o

f EN

6007

9-11

(lat

est e

ditio

n).

23

14

23

14

B1

B2

Saf

e A

rea

App

arat

us(s

ee N

ote

1)Ze

ner

Dio

de S

afet

y B

arrie

rsM

TL 7

755a

cB

AS

99

ATE

X 72

17

Not

e 2b

The

capa

cita

nce

and

eith

er th

e in

duct

ance

or t

he in

duct

ance

to re

sist

ance

(L/R

) rat

io o

f the

cab

leco

nnec

ted

betw

een

3 &

4 o

f an

MTL

775

5ac

zene

r di

ode

safe

ty b

arrie

r pl

us te

rmin

als

3 o

f ase

cond

MTL

775

5ac

zene

r di

ode

safe

ty a

nd te

rmin

als

barr

ier

2, 3

& 6

of a

kat

haro

met

er T

ype

0065

XX, m

ust n

ot e

xcee

d th

e fo

llow

ing

valu

es:

PO

WE

R S

UP

PLY

TYP

E 4

234

500/

501

CE

RTI

FIE

D [E

x ia

Ga]

IIC

(–20

°C≤

Ta ≤

+55

°C)

CE

RTI

FIC

ATE

No

BA

S 0

1 AT

EX

7041

- +4

–1+ 9 10 3

–

2+

KAT

HA

RO

ME

TER

TYP

E 0

065X

XX

CE

RTI

FIE

D E

x ia

IIC

T4

Ga

CE

RTI

FIC

ATE

No

BA

S 0

1 AT

EX

1042

(–20

ºC ≤

Ta

≤ +

55ºC

)

and

IEC

Ex

BA

S 0

4.00

25

…4 INSTALLATION

Fig

. 4.5

PS

U in

Ass

oci

atio

n w

ith

a K

atha

r om

eter

and

Oth

er S

afe

Are

a A

pp

arat

us w

ithT

wo

Zen

er D

iod

e B

arri

ers

17

5 MAINTENANCE AND SERVICING

5.1 General

Warning.

• This unit forms an integral part of a certified intrinsicallysafe system. Appropriate safety precautions must be takento prevent any incendive electrical discharges in thehazardous area when carrying out any of the followingtasks.

• The maximum pressure and temperature limits specifiedfor particular parts of the system must not be exceeded.

Note. After any service, repair or modification, the suitablyqualified personnel involved must certify that the equipmentis in a safe state.

The katharometer unit and its associated equipment aredesigned for stable and accurate operation over long periods. Itis not normally necessary to check the accuracy of the systemmore than once a month, and in most cases experience willshow that this period may be extended.

Apparently false or unstable readings may occur due to faults inthe installation of the measuring system. These possible sourcesof error are summarised below.

5.2 Sources Of Error In Readings5.2.1 PressureThermal conductivity does not vary significantly over a very widerange of pressure but large deviations from atmosphericpressure can be significant. Gases containing large molecules(such as carbon dioxide) are the most sensitive to pressurechanges. High pressure samples should be passed through areducing valve and analysed at atmospheric pressure.

5.2.2 FlowThe katharometer zero balance and sensitivity are independentof the sample flow rate, since gas enters the katharometer cellsby molecular diffusion. Speed of response of the analyser is,however, affected by the flow rate. It is advisable to limit the rateto below 500 mI min–1, the usual setting being about150 mI min–1. In installations where an absorption or dryingchamber is fitted, a compromise has to be made to avoid toorapid consumption of the absorbing or drying material withoutexcessive loss of response speed. For most applications, it isrecommended that the flow be greater than 50 mI min–1. Care isnecessary in the design of sample pipes for very low flow rates:if the flow is less than 50 mI min–1, precautions must be taken toavoid gases absorbing and/or desorbing from the surface of thepipeline, or pipeline permeability effects.

5.2.3 LeaksLeaks in the pipework installation must be avoided especiallywhen the gas sample is below atmospheric pressure. On akatharometer with reference air zero, a leak will have little effectat zero, but will become more noticeable on upscale readings.The total effect will be an apparent loss in instrument sensitivity.A leak can often cause spurious instability which is not due to afault in the katharometer.

5.2.4 VibrationVibration does not normally affect a katharometer, but ifpulsation of the sample flow produces a resonance in thekatharometer cells, errors can arise due to cooling of thefilament.

5.2.5 ImpuritiesThe most likely source of error in an otherwise correctlyoperating system is the presence of an impurity in the sample,i.e. the katharometer has been calibrated without knowledge ofthis impurity. The impurity could arise from the use of rubber orplastic sample tubes, for example, which can causecontamination from the surface of the tube. For this reason,stainless steel tubing is recommended. A further possibility is theunexpected presence of water vapour in a supposedly drysample gas or, conversely, lack of saturation in a wet gas.

Errors may also be introduced due to deposition on thefilaments, indicating that the sample has not been adequatelyfiltered before entering the katharometer. Such contaminationcan be compensated for by adjustment of the zero control, andwill not produce serious errors until the range of zero adjustmenthas been exhausted.

5.2.6 SamplingErrors due to faulty sampling can result in false indications of thetrue conditions. This is particularly important where thekatharometer forms part of a process control loop.

When wet gases are being sampled, it is important to ensurethat there are no points in the system where condensate canbecome trapped causing blockage. It is recommended thatstainless steel sample tubing is used wherever possible, andthat the katharometer be installed as close to the sampling pointas is practicable.

5.2.7 Temperature VariationsThe katharometer zero balance is not substantially affected bytypical variations in ambient temperature, since thekatharometer is both electrically and thermally symmetricalwhen the same gas surrounds the four filaments. Variations inSensitivity due to temperature changes can, however, occur.These can reduce accuracy particularly on sensitive ranges. Thegreater the difference in conductivity temperature coefficients ofthe sample constituents, the greater will be any sensitivity errorcaused by a temperature change. To overcome such problemsa thermostatically controlled katharometer is recommended(Models 6518 or 6520).

The temperature of a gas at the sampling point has ‘little effecton the measurement unless it is unduly high and the samplingtube is very short; in any case the errors are small. If necessary,the sample pipe should be extended to 1 or 2 metres to allow thegas to cool.

18

…5 MAINTENANCE AND SERVICING

5.2.8 Bridge CurrentThe katharometer bridge working current is normally 350 mAand is supplied by a stabilised power supply unit. It is essentialthat the working current remains stable during operation, sincethe output of the katharometer is approximately proportional tothe cube of the bridge current.

5.3 Zero AdjustmentThe zero balance of the katharometer is set during manufacture.At periodic intervals this zero balance should be checked. Achange in zero has the effect of displacing all parts of the scaleby an equal amount, and can thus be corrected by setting theindicated reading to any known concentration being sampled.Whenever necessary the katharometer must be calibratedagainst a pure gas or a readily available reference gas.Alternatively, the reading may be set against an accuratechemical analysis of the gas. To adjust the zero, first set the zeroof the indicating device and then, with the zero (reference) gaspassing through the katharometer, adjust the zero control on thekatharometer unit (it is not necessary to remove the cover to dothis) until the desired value is indicated; a clockwise rotationproduces an upscale change in reading.

5.4 Sensitivity AdjustmentThe sensitivity of a katharometer unit is stable and no attemptmust be made to adjust this. The multiturn potentiometer, R7,(typically 500 ohms or 200 ohms – see Fig. 1.2) is sealedfollowing adjustment at the factory. On two range versions, anadditional potentiometer for the second range is also preset andsealed as appropriate. No responsibility will be accepted by ABBfor the performance of any katharometer on which thepotentiometer seals have been broken.

5.5 Damaged Or Flooded KatharometerIf the indicated reading from a katharometer moves suddenlyhard up or down scale when the unit is sampling a gas known tobe within its measurement range, the cause may be a brokenkatharometer filament or the katharometer cells becomingflooded with water – see Section 5. A rapid way to determine thisis to measure the voltage across the katharometer bridge. If thevoltage across terminals 1 and 4 on the katharometer unit ismore than 4 V with 350 mA passing, one filament could bebroken: two filaments broken cause a reading permanently atone end of the scale with no response to the zero adjustment. Afilament which is damaged but not broken will give erroneousreadings which vary when the instrument is tapped lightly.

Caution. Do not insert any type of probe into the gassample pipes on the katharometer units, and especially notthe filament cells. In cases of difficulty contact themanufacturers, quoting the instrument number and givingfull particulars of the problem.

If the katharometer unit is accidentally flooded with water, orcondensed water vapour accumulates inside the katharometerblock due to inadequate filtering, the indicated reading will movehard up or down scale and the voltage measured acrossterminals 1 and 4 will be less than 2.8 V with 350 mA bridge

current passing. Water is difficult to remove from a katharometer,but may be attempted as follows:

1) Disconnect the katharometer unit completely from itshousing.

2) Turn the unit upside down and raise the inlet so that the blockis at an angle of 45° – drain of any excess liquid.

3) Pour a little rectified spirit, ethyl alcohol or methylated spiritsthrough the katharometer. Allow as much liquid as possibleto drain out – gentle shaking will assist.

4) Repeat step 3) several times.

5) Replace the katharometer unit and if this is a thermostaticallycontrolled type (Model 6518) connect the heater supply(terminals 7 and 8) and the bridge supply (terminals 1 and 4).If the katharometer is a thermally lagged type, connect thebridge supply (terminals 1 and 4) only.

6) Pass dry air or other readily available dry gas through thekatharometer. It is possible for the instrument to take a day ormore to dry out completely: the zero may also drift for severaldays.

Caution. If the fault is traced to a broken or damagedfilament, the complete unit must be returned to the factoryfor repair or replacement. Do not attempt to repair orreplace a katharometer cell.

19

tluaF esuaCelbissoP tseTrokcehC

gnidaerwoL oreztcerrocnI

enilepipnikaelriA

tinuylppusrewopmorftuptuowoL

detsuahxetnacciseD

detsuahxetnebrosbasaG

tcerrocnirosaggnirefretnidetcepxenufoecneserPfoemittayrotcafotdeifitonsnoitidnocelpmas

noitarbilac

ro815600sledoM(gnikrowtonlortnocerutarepmeT)ylno025600

.redrocer/rotacidnifoorezlacinahceM.retemorahtakfooreZ

.snoitcennocepipllA

.launamnoitcurtsnitinuylppusrewopeeS

.tnaccisedecalpeR

.tnebrosbaecalpeR

tnesatadkcehC.BBAtlusnocrosaggnirefretnievomeR.BBAtlusnocdnaredrohtiw

tiucricneporofrorotsisnartrewopkcehC.tohooT.rotsimreht

gnidaerhgiH oreztcerrocnI

tinuylppusrewopmorftuptuohgiH

detsuahxetnacciseD

tcerrocnirosaggnirefretnidetcepxenufoecneserPfoemittayrotcafotdeifitonsnoitidnocelpmas

noitarbilac

dna815600sledoM(gnikrowtonlortnocerutarepmeT)ylno025600

.redrocer/rotacidnifoorezlacinahceM.retemorahtakfooreZ

.launamnoitcurtsnitinuylppusrewopeeS

.tnaccisedecalpeR

.BBAtlusnocrosaggnirefretnievomeR.BBAtlusnocdnaredrohtiwtnesatadkcehC

tiucrictrohsrofrogniriwylppusrewopkcehC.dlocooT.rotsimrehtrorotsisnart

tagnidaeRorezraenro

redrocer/rotacidniytluaF

tinuylppusrewopmorftuptuooN

riacirehpsomtanigniwarD

?noylppusrewopredrocer/rotacidniehtsI

nitiucricnepO.launamnoitcurtsnitinuylppusrewopeeS.snoitcennocgniriw

.skaelrofgnipipkcehC

gnidaeRdrah

elacspu

foegnartnemerusaemedistuonoitartnecnocelpmaSretemorahtak

)s(tnemalifnekorB

.sisylanatnednepedniybkcehC

,stlov4nahteromsi4dna2slanimretssorcaegatlovfI.riaperrofretemorahtaknruter

gnidaeRdrah

elacsnwod

foegnartnemerusaemedistuonoitartnecnocelpmaSretemorahtak

tinuylppusrewop/redrocer/rotacidniotsnoitcennoCdesrever

)s(tnemalifnekorB

retawhtiwdedoolfretemorahtaK

.deriuqernehwdetcennoctonlortnocorezlanretxE

.sisylanatnednepedniybkcehC

.tinuylppusrewop/redrocer/rotacidniotgniriwkcehC

,stlov4nahteromsi4dna1slanimretssorcaegatlovfI.riaperrofretemorahtaknruter

,stlov8.2nahtsselsi4dna1slanimretssorcaegatlovfI.riaperrofretemorahtaknruterrotuoyrd

orezetomerrofdeilppusneebsahretemorahtakfikcehC.)2.1.giFoslaees(tnemtsujda

5 MAINTENANCE AND SERVICING…

5.6 Fault FindingThe following is a list of faults which may occur on a katharometer installation, together with their possible causes and remedies:

20

metI 000715600 000815600 J/069935600 K/069935600 100845600

epip.d.omm4roftikgnilpuocdaehkluB

daehklubotkcolbretemorahtak(epipgnitcennoC)gnilpuoc

531525600

081715600

800845600

081715600

metIrebmuNtraP

006525600 300845600

)lm041(rebmahccilyrcA

gnidulcni(tiktnemhsibrufeR)ezuagdnaslaes

017525600

506525600

027525600

700845600

metI rebmuNtraP

zH06/05V032pmupelpmaS

zH06/05V511pmupelpmaS

tikmgarhpaiddnagnirps,evlaV

300073200

400073200

521045600

6 SPARES

The following is a list of spare parts for the principle items used on typical katharometer assemblies. Enquiries and orders for sparesshould be addressed to ABB.

6.1 The Katharometer Unit

6.2 Drying Absorption Chamber 6.3 Gas Sample Pump

tluaF esuaCelbissoP tseTrokcehC

citarrEsgnidaer

tinuylppusrewopmorftuptuoydaetsnUdnaretemorahtakneewtebsnoitcennocgniriW

.tinuylppusrewop/redrocer/rotacidni

tnemalif)nekorbtontub(degamaD

gniriwnipukcipecnerefretnI

skaelriA

yltcerrocgninoitcnuftontiucriclortnocerutarepmeT)ylno025600dna815600sledoM(

wolfelpmascitarrE)dettiffi(rotaripsaniwolfretawralugerrI

.launamnoitcurtsnitinuylppusrewopeeS.snoitcennocgniriwkcehC

,osfi;segnahcgnidaerfikcehcotylthgilkcolbehtpaT.riaperrofretemorahtaknruter

rehtehwhsilbatseotsdaelrotacidnitcennocsiDmorfroretemorahtakehtmorfsetanigiroecnerefretni

.selbacdeneercsesu,rettalehtfI.sdaelgniriwnipukcip

.skaelrofgnipipkcehC

erutarepmetnitluaF.tinuylppusrewopotsnoitcennoCrewopdnarotsimrehtyllaicepsekcehc-tiucriclortnoc

.rotsisnart)dettiffi(gnidaereguagwolfevresbO

.rotaripsaotylppusretawkcehC

wolSotesnopser

nisegnahcelpmas

noitartnenoc

partetasnednocata.g.e,dekcolbyllaitrapenilepiP

)dettiffi(tcerrocnirotaripsawolfretaW

.gnipipkcehC

?epipliatrotaripsaehtmorfgniwolfretawsIssalgehtniselbbubfowolfsuounitnocralugeraerehtsI

.yrassecensaylppusretawtsujdA?rebmahc

sgnidaeRotevitisnesnisegnahc

wolf

wolfnisegnahcotevitisnestonsiretemorahtakehTretawfossergni,skaelriaebdluocesuacehT.etar

epipelpmasfosllawnosagfonoitneterroruopav

htiwsepipcitsalprorebburllaecalpeR.skaelrofkcehC.leetssselniats

…5 MAINTENANCE AND SERVICING

Products and customer supportAutomation SystemsFor the following industries:— Chemical & Pharmaceutical— Food & Beverage— Manufacturing— Metals and Minerals— Oil, Gas & Petrochemical— Pulp and Paper

Drives and Motors— AC and DC Drives, AC and DC Machines, AC Motors to

1kV— Drive Systems— Force Measurement— Servo Drives

Controllers & Recorders— Single and Multi-loop Controllers— Circular Chart and Strip Chart Recorders— Paperless Recorders— Process Indicators

Flexible Automation— Industrial Robots and Robot Systems

Flow Measurement— Electromagnetic Flowmeters— Mass Flowmeters— Turbine Flowmeters— Wedge Flow Elements

Marine Systems & Turbochargers— Electrical Systems— Marine Equipment— Offshore Retrofit and Refurbishment

Process Analytics— Process Gas Analysis— Systems Integration

Transmitters— Pressure— Temperature— Level— Interface Modules

Valves, Actuators and Positioners— Control Valves— Actuators— Positioners

Water, Gas & Industrial Analytics Instrumentation— pH, Conductivity and Dissolved Oxygen Transmitters and

Sensors— Ammonia, Nitrate, Phosphate, Silica, Sodium, Chloride,

Fluoride, Dissolved Oxygen and Hydrazine Analyzers— Zirconia Oxygen Analyzers, Katharometers, Hydrogen

Purity and Purge-gas Monitors, Thermal Conductivity

Customer supportWe provide a comprehensive after sales service via a Worldwide Service Organization. Contact one of the following offices for details on your nearest Service and Repair Centre.

UKABB LimitedTel: +44 (0)1453 826661Fax: +44 (0)1453 829671

USAABB Inc.Tel: +1 215 674 6000Fax: +1 215 674 7183

Client WarrantyPrior to installation, the equipment referred to in this manual must be stored in a clean, dry environment, in accordance with the Company's published specification.Periodic checks must be made on the equipment's condition. In the event of a failure under warranty, the following documentation must be provided as substantiation:— A listing evidencing process operation and alarm logs

at time of failure.— Copies of all storage, installation, operating and

maintenance records relating to the alleged faulty unit.

Contact us

IM/6

517–

6518

Rev

. H01

.201

7ABB LimitedIndustrial AutomationOldends LaneStonehouseGloucestershire GL10 3TAUKTel: +44 1453 826 661Fax: +44 1453 829 671

ABB Inc.Industrial Automation125 E. County Line RoadWarminsterPA 18974USATel: +1 215 674 6000Fax: +1 215 674 7183

www.abb.com

NoteWe reserve the right to make technical changes or modify the contents of this document without prior notice. With regard to purchase orders, the agreed particulars shall prevail. ABB does not accept any responsibility whatsoever for potential errors or possible lack of information in this document.

We reserve all rights in this document and in the subject matter and illustrations contained therein. Any reproduction, disclosure to third parties or utilization of its contents in whole or in parts – is forbidden without prior written consent of ABB.

Copyright© 2017 ABBAll rights reserved