Gas Analyzers 2 - RMT Ltd 2.pdf · DX6101 Controller Module DX6106 Optical Unit DX6102...

Gas Analyzers 2 .2

RMT

Ltd.

Components for Gas Analysis2

Contents

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Modular Gas Analyzer DX6100 Series . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23Advantages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23

Design Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24Principles of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24Operation Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25Noise level . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25Inside the Analyzer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26

Output Connectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26Functional Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26DX6102 Optocomponent Mating Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27DX6106 Optical Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27DX6101 Controller Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27

Working with DX6100 Analyzer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28DX6100 Vision II Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28System Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28Zero Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29Parameters of Analyzer Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29

Housing and Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31

Common . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31Carbon Dioxide (CO2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31Hydrocarbons (CnHm) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32Methane (CH4) selective . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32

Standard Kits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32DX6100 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32DX6100 OEM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32

RMT Ltd.

DX6100 Series

23

Components for Gas Analysis

53 Leninskij prosp. Moscow 119991 Russia u phone: 7-095-132-6817 u fax: 7-095-132-5870 u e-mail: [email protected] u http://www.rmtltd.ru

Gas

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rsThe company RMT Ltd introduces DX6100series of Modular and OEM non-dispersiveinfrared (NDIR) Gas Analyzers.

The principle of operation is based on selectiveabsorption of IR radiation by gas molecules.

The differential double frequency opticalscheme provides a high accuracy in wide rangesof humidity and temperature due to the internalthermostabilization.

A new type of middle infrared (IR) integratedOptopair (Detector and Light Emitters) with built-inthermoelectric cooling is used.

The light sources are pulsed solid state mid-dle-IR Light Emitters. The Photodetector is basedon the Lead Selenide (or Lead Sulphide) photore-sistor.

There are several models suitable for the fol-lowing gases: CO2, CH4, CnHm.

Other optional gas analyzers are available onrequest.

Both complete modular and OEM versions areavailable.

Advantages

u High selectivity and stabilityu Wide range of measured concentrationsu Small gas sampling cellu Fast responseu Long service lifeu No moving partsu Miniature design and small weightu Low power consumption

Modular Gas AnalyzerDX6100 Series

RMT Ltd.

DX6100 Series

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The Non-Dispersive Infra-Red Spectroscopy (NDIR)measurement method is implemented in the DX6100Analyzer.

The analyzer provides gases concentration meas-urement based on the classical double channel opticalscheme.

One of the beams (measuring channel) has thewavelength tuned to the optical absorption line of themeasured gas. The other beam (reference channel)has the wavelength that is out of the adsorption band ofthe measured gas.

After passing through the gas sampling cell the twolight beams intensities are compared.

The reference channel is used for indirect measur-ing of the initial light intensity and allows to eliminate

actual measurements conditions: total transparency ofgas volume, optics imperfection and so on.

The principle of gas concentration measurement realized inthe DX6100 analyzer

The DX6100 Gas Analyzer is specially designed forfast response, high sensitivity, low noise and low powerconsumption.

A number of design features contribute to the per-formance :

u The infrared sources are special narrow-bandpulsed Light Emitters operating in a microsec-ond range. The light sources have long life(more than 10,000 hours).

u Radiation from Light Emitters passes throughgas sampling cell, reflects from the mirrors andis focused onto wide-band Photodetector.

u Light Emitters and Photodetector chips are inte-grated into a single housing and placedonto a miniature TE cooler for ther-mostabilization.

u Microcontroller provides temperatureregulation with better then 0.1°C accura-cy. The temperature is software selec-table from the ambient value down to–20°C.

u Heat dissipated from the warm side ofTE coolers results in few degrees ofoverheating of gas sampling cell abovethe ambient. This factor plays the role ofvapor anti-condensation at high moistureoperation.

u All driving function of Light Emitters and

Detector are operated by the on-board micro-controller.

u Pre-amplified outputs are maintained by themicrocontroller. The final result is digital data ofmeasured gas concentration and is available inrealtime through the RS-232C or an analog port.

u For the signal processing the calibrated data ofOptical Unit is used. The data is stored in OpticalUnit’s EEPROM.

u The RS-232C port is also used for the remotecontrol from a computer.

Principles of Operation

Design Features

Noise level

Operation Overview

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DX6100 Series

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The order of measurements with the DX6100 deviceis as follows:

1. The individual calibration of device is requiredusing standard gas mixtures.

The Detector output signal is non-linear with respectto the measured gas concentration. The intensity oflight that passed through the gas sampling cell is theintegral of various optical rays from Light Emitter. Thesensitivity of Detector and performance of Light Emitterdepend very much on their operating temperatures.

The Detector output signals (both measuring andreference channels) are measured while calibrationgases with known concentration are passing throughthe gas sampling cell. The data obtained are used forpolynomial extrapolation of calibration results.

The polynomial coefficients and the “zero” ratio arestored into the device internal on-board EEPROMmemory.

The first calibration is made by the manufacturer.The factory standard calibration uses not fewer than

five standard gas mixtures.Several calibrations are made at different ambient

temperatures (in the specified operating range) and atcorresponding optimal operating temperatures of theintegrated Detector-Emitter pair.

It is possible to store up to 15 such calibrations forfurther application.

2. During a routine operation the detector outputsignals are measured. Using a known “zero” value andpolynomial coefficients the gas concentration is calcu-lated with a high accuracy as a function of measuringand reference channels signals ratio.

Resulted concentration is calculated in absolutemmol/m3 units.

The device provides (if required) recalculation of theconcentration into relative ppm units. But to convertabsolute units (mmol/m3) into relative (ppm) ones it isnecessary to know ambient temperature and pressure.

The values of ambient temperature and pressurecan be inputted by a user manually into the devicememory at the beginning of the experiment.

Default values are extracted by the device micro-controller from the memory and correspond to theambient conditions at calibration procedure.

It is also possible to use the value of measuredambient temperature provided by the on-board digitalthermosensor.

3. To preserve high accuracy of the device it is nec-essary to make “zero” adjustments periodically as rec-ommended in the DX6100 User’s Guide.

4. Periodicity of the device recalibration is 1 year. Itcan be done at the Manufacturer’s factory or by a userwith the help of the corresponding DX6100 Vision IIsoftware.

Adjustable noise level is realizeddue to application of digital filtrationalgorithm.

The main parameter of the digi-tal filter is Time constant. It isadjustable in the range 0.1…60 s.

310

330

350

370

390

1 31 61 91 121 151Time, s

CO 2 C

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ppm

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1 31 61 91 121 151Time, s

CO 2 C

once

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tion,

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1 31 61 91 121 151Time, s

CO 2 C

once

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1 31 61 91 121 151Time, s

CO 2 C

once

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tion,

ppm

Time constant=0.1 s

Time constant=0.2 s

Time constant=1.0 s

Time constant=5.0 s

Functional Diagram

Output Connectors

Inside the Analyzer

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DX6100 Series

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The DX6100 Analyzer consists of three mainparts:

u DX6106 Optical Unitu 6101 Controller Moduleu 6102 Optocomponent Mating ModuleThose parts combined together and housed into a

body form a complete version of the DX6100Analyzer.

The same components taken separately, supple-mented by a set of special cables, form a Kit for OEMapplications (DX6100 OEM) analyzer.

There are the following units on the front panel ofthe DX6100 Analyzer:

u Power supply input connectoru RS-232 connectoru Analog output connectoru Two-color LED indicatoru Inlet and outlet gas ports

DX6100 Analyzer, the cover removed

Functional Diagram of the DX6100 Gas Analyzer

Output Connectors

The DX6102 Optopair Mating Module is connectedwith DX6101 Controller Module by special cable viaminiature 20 pin System Interface connectors.

Digital Thermometer is an optional module for themeasurement of the absolute value of ambient temper-ature with 0.5°C accuracy.

DX6101 Module

Supplyinput

Two-colorLED

RS232Port

Analogoutput

Gas outletport

Gas inletport

Gas samplingtube

DX6101Optical Unit

DX6102Module

DX6101 Controller Module

DX6106 Optical Unit

DX6102 Optocomponent Mating Module

RMT Ltd.

Inside the Analyzer

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The 6010 Controller Module provides the followingfunctions:

u Amplification and processing of Detector’s out-put signals

u Storage of identifier and individual calibrationparameters

u Thermostabilization of Optopair using built-inPID driving algorithm of built-in TE cooler withthermosensor signals forming for Light Emittersdriving

u Filtering and digitizing of Detector pre-amplifiedoutput

u Conversion of amplified output signals into gasconcentration value using the stored calibrationdata

u Driving by the gas analyzer through the RS-232port

u Light and sound alarm.

6101 Controller Module

Optical Unit

DX6106.C4 Sampling CellDX6106.C2 Sampling Cell

The DX6106 Optical Unit is the head part of the GasAnalyzer. It consists of an isolated gas sampling cell(the spherical mirror and the sapphire window areplaced at the end sides) and a new generation integrat-ed optopair with the DX6102 electronic mating module.

The internal volume of the gas cell depends on theOptical Unit version. The gas sampling cell has two gasinlets with 5.0 mm internal diameter.

The gas sampling cell can be easily disassembledfor the service of the internal optics (mirror and win-dow). For this purpose both the top and bottom coverscan be removed and the optical components extracted.

The mirror has a special SiO2 safety layer.The DX6106 Optical Units are manufactured in two

versions: with DX6106.C2 and DX6106.C4 gas sam-pling cells (See Table).

Depending on what gas and what limiting concentra-tion value must be measured, it is furnished with one orthe other sampling cells.

The DX6102 Optocomponent Mating Moduleprovides:u Pre-amplification of photodetector’s sig-

nalsu Light Emitters drivingu Power supply of Photodetector and

Thermistors with precise voltage supplyDX6102 Mating Module

Gas samplingcell

Number ofpasses

Total pathlength, mm

Internal volume,ml

DX6106.C2 2 25 1DX6106.C4 4 85 10

System Requirements

DX6100 Vision II Software

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Dx6100 Series

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In general nothing is required for the Analyzer oper-ation except the external power source.

But for many purposes, such as the change of tun-ings of the analyzer, zero adjustment, calibration andso on, the control computer is necessary.

A user can control the Analyzer with computer in twoways:

1) The remote control by the Analyzer is availableusing the RS-232 port by a set of microcontroller com-mands.

The commands can be divided into two groups:

driving commands and setting commands.All commands have the same format – the symbol

string, which consists of the command name identifierand a list of its parameters. Some commands have noparameters. The commands are described in User’sGuide.

This way is very useful if a user is going to integratethe DX6100 analyzer into a more complicated system.

2) The second way is based on using the DX6100Vision II software.

The DX6100 Vision II software provides all possibleoperational modes of the DX6100 Gas Analyzer. The soft-ware has a simple interface and does not demand aUser's special knowledge.

The software is delivered with the DX6100 GasAnalyzer.

Also it is available for free dawnload from RMT website:

www.rmtltd.ru

To run the DX6100 Vision II softwarethe following system requirements mustbe met or exceeded:

u Intel Pentium class computer withWindows 95/98/2000 operatingsystem

u Free COM portu 16 MB of RAM (32 MB recom-

mended)u 6 MB free hard drive spaceu CD ROM driveu Mouse or compatible pointing

device

Working with DX6100 Analyzer

Setup Window

Main Window

Parameters of Analyzer Adjustment

Calibration

Zero Adjustment

RMT Ltd.

DX6100 Series

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The DX6100 Vision II program allows an adjustmentof various operation parameters of the device. The fol-lowing parameters are among them:

u Parameters of Light Emitters and Photodetectoroperation (pulse duration, Emitter current,Detector gain, synchronization and others)

u Telemetry structure (output parameters, repeat-ing rate, duration of measurements and others)

u Warning levelsu Analog output adjustment and othersBut before editing a parameter study the device

description thoroughly, please. Many of availableparameters should be adjusted very carefully by experi-enced users only or along the manufacturer’s recom-mendation.

One of the very useful utility of the DX6100 Vision IIsoftware is Calibration subroutine.

The program allows users to carry out quite a com-plex procedure of the device calibration.

The first calibration in a specified concentrationrange is made by the manufacturer.

A user can perform any recalibration with the use ofthe program.

According to the instructions the procedure consistsof several steps that must be completed by a user.

First of all, a user need to have a set of standardgases with concentrations in specified range. Then auser is to start the Calibration program and followinstructions step-by-step.

The advisable periodicity of the device recalibrationis 1 (one) year. It could be done at the factory of themanufacturer or by a User with the help of DX6100Vision software.

To ensure high accuracy, a simple adjustment canbe made during operation to adjust the “zero” ratio.

The procedure requires to start the sensor in theCalibration mode and to flow up any "zero" gas throughthe gas sampling cell.

The new “zero” coefficient will be stored in EEPROMin place of the old value after the adjustment procedureis complete.

Setting Window

Calibration Procedure

Housing and Dimensions

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DX6100 Series

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The enclosure of the Analyzer ismade of a painted aluminum alloy.

The extruded body of the enclo-sure is closed by covers from endfaces.

The rubber gaskets placedbetween the body and covers providethe enclosure with water resistance.

DX6100 Analyzer Outline Dimensions (in millimeters)

DX6106.C2 Optical Unit Outline Dimensions(in millimeters)

DX6106.C4 Optical Unit Outline Dimensions(in millimeters)

Carbon Dioxide (CO2)

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DX6100 Series

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Type NDIR Gas Analyzer

Detector Lead Selenide with TE coolerMeasured Gases (available options)

Carbon Dioxide CO2Hydrocarbons CnHm

Methane CH4Timing

Output Repeating Rate 0.01…20 HzAverage Time Constant 0.1…60 sec

AlarmsLight Two-color LED

Sound >85 dBSupply Requirements

Voltage +6 to +15 VDCCurrent 300 mA (max)

InterfaceDigital RS-232C

Analog 0…4095 mVOperation Conditions

Moisture Protection IP65 (excluding OEM version)Temperature Range -10 to +50 oC

Relative Humidity 5 to 100%Mechanical (Modular Option)

Dimensions 60x80x122 mmWeight 310 g

Mechanical (OEM Option)Dimensions

DX6101 Controller Module 80x43x14 mmDX6102 Mating Plate 47x26x8 mm

DX6106.20 Sampling Cell 34x32x27 mmDX6106.40 Sampling Cell 40x36.5x27 mm

Mounting Base 135x48x3.5 mmWeight

DX6101 Controller Module 24 g (max)DX6102 Mating Plate 8 g (max)

DX6106.20 Sampling Cell 50 g (max)DX6106.40 Sampling Cell 55 g (max)

Mounting Base 20 g (max)

Concentration Range 1) 0…1000 ppm 0…5 %vol 0…20 %volNoise Level 2,3) < 3 ppm < 0.15 % < 0.15 %Accuracy 3) 10 ppm 0.50% 0.50%Zero Drift 3) 0.02%

Information furnished by RMT Ltd is believed to be reliable. However, no responsibility is assumed for possible inaccuracies oromission. Specifications are subject to change without notice.

Common

Specifications

DX6100 OEM

DX6100

Standard Kits

RMT Ltd.

Specifications

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Specifications (...continued)



# Item Code Q-ty, pcs1 Gas Analyzer DX6100 12 Power supply cable DX6100-C-02 13 RS-232 cable DX6100-C-03 14 Analog interface cable DX6100-C-04 15 AC/DC adaptor 16 DX6100 User Manual 17 DX6100 Vision software CD 1

# Item Code Q-ty, pcs1 Optical Unit DX6106.xx 12 Controller module DX6101-x.xx 13 Optopair mating module DX6102-x.xx 14 Module interconnect cable DX6100-C-11 15 Power supply cable DX6100-C-12 16 RS-232 cable DX6100-C-13 17 Analog interface cable DX6100-C-14 18 AC/DC adaptor 19 DX6100 User Manual 110 DX6100 Vision software CD 1

Notes:1) Optional concentration ranges are available on request.2) At Averaging Time Constant= 0.2 s.3) If value in %, then it means relative units.4) Software adjustable.

Methane (CH4) selective

Hydrocarbons (CnHm)

RMT Ltd.

Notes

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RMT Ltd.



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Gas Analyzers 2 - RMT Ltd 2.pdf · DX6101 Controller Module DX6106 Optical Unit DX6102...

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