BY :SELAMAT SURIYADI

GAS DETECTOR

Content Of Presentation

Introduction

Conclusion

About Gas Detector

Characteristic of Combustible gases

5 % GAS

4 % GAS

3 % GAS

2 % GAS

1% GAS

0 % GAS

100 % LEL

80% LEL

60 % LEL

40% LEL

20% LEL

0 % LEL

15 % LEL

LELGas to Air mixture EXPLOSION

LEAN

Introduction

Combustible Gas Detection

Two types of combustible gas detection are :

• Catalytic

• Infrared Absorption

Hydocarbon

Oxidizes

Heat Resistance

Platinum Wheatstone Bridge

Voltage

Catalytic Combustible Gas

INFRARED DETECTORS

RAY SEPARATOR

IR TRANSMITTER

REFERENCE RECEIVER

MEASURING RECEIVER

GAS

Advantages Of General Monitors

Robust

Simple to operate

Easy to install, calibrate and use

Easily calibrated individually to gases such as hydrogen which cannot be detected using

Use for safety devices.

Use to indicating of presence combustible gas.

CONCLUSION

THANK YOU

Selamat Suriyadi MTT-14 instrument

Calibration of General MonitorsCalibration may be carried out as follows :

1. “ - - -” 2. “AC”3. “CP”. 4. “CC5. “0”.

GENERAL MONITORSThe General monitors model S4100C is highly reliable .It is designed to measure and display concentration of combustible gases in the range of : 0%-100%(LEL)

Where : For CH4 , Alarm = 20% LEL And Action = 50% LEL (API)

Selamat Suriyadi MTT-14 instrument

Gas Detection in EDG Area FSZ-41

Selamat Suriyadi MTT-14 instrument

Trip instr. air compressor 7-X-

3210-A

Trip instr. air compressor 7-

X-3210-B

Trip N2 Generation

Package 7-X-3300-B

Trip N2 Generation

Package 7-X-3300-A

Gas Detection in EDG Area FSZ-41

Stop and inhibit starting of EDG

7-EDG-3160

Close phase-4 plant air utility distr.

Level 2

Level 1

ESD LOGIC GAS DETECTOR IN EDG AREA FSZ-41

2oo3 2oo

3

SPECIFICATION

Type : Standard Industrial Hydrocarbon Sensor

Electric Classification : NEC and CSA ,class I ,Division I ,group B, C and D

Response Time : Typically 6-second time constant when exposed to 50% LEL of methane gas.

Model : S4100C Part.N 31100, Eexem II T5, Eexem II T4

        CONDITION        RESULT

 

No   INHIBIT 

FAULT    DETECT TRIP

NO TRIP

  GD 1 GD 2 GD 3 GD 1 GD 2 GD 3 GD1 GD 2 GD 3    

1                      

2                      

3                      

4                      

5                      

6                      

7                      

8  

          

VOTING SYSTEM 2oo3

Gas detector location and tag numberingThere are 3 Gas Detectors,4 Heat Detectors and 2 Fire

Detectors On EDG-1360 AREA FSZ-41

GD-9024 on H-6320GD-9025 on P-6310AGD-9026 on P-6310B

Voting system 2oo3

HD-9000HD-9001HD-9002HD-9003FD-9022FD-9023

Selamat Suriyadi MTT-14 instrument

7Formation Girassol

IR SPOT SENSOR

When a combustible gas passes through an IR radiation with a wavelength # 3.4 µm, gas molecules absorb a part or IR radiationThis absorption depends on the concentration and on the type of the gasIt can be used if concentration > UELAlternate to catalytic sensors in poisoning atmospheres

21/06/2009

For CH4, alarm = 20 % LEL and action = 50 % LEL (API)

MirrorGas

IRTransmitter

ReferenceReceiver

Measuringreceiver

Mirror

Rayseparator

Selamat Suriyadi MTT-14 instrument

General Monitors location Guidelines• Consider how the leaking gas will

disperse.• Consider the emission temperature and specific gravity of the gas to be detected.

• Select sensor accessories so as to protect the sensor against high wind velocities, rain,

dust,hosing down and any other anticipated

environmental hazards.

SPECIFICATIONS

Selamat Suriyadi MTT-14 instrument

Combustible Material

A combustible material is a solid , liquid, or gas that may undergo the chemical reaction of combustion. Combustion occurs when an organic chemical is oxidized to produce energy, water, and carbon dioxide.

there are nine Fault conditions that are monitored by the microprocessor, as follows:

F2 Failed to Complete CalibrationThis Fault will occur if the unit is placed in the calibration

mode and no gas has been applied within six minutes, or if gas has been left on for more than six minutes.

ACTION – Remove gas, if present. Apply the magnet to the GM Logo on the cover to clear the fault. Attempt to calibrate.

F3 EEPROM Checksum ErrorThis fault indicates that the contents of the Model

S4000C’s program memory have changed. This usually occurs, when powering the unit up after a lightning strike or large voltage transient on the power or signal lines to the unit.

ACTION - The unit must be returned to the factory or authorized service center for repair.

F4 Sensor ErrorThis fault indicates that either one of the remote sensor

leads is open or shorted, or that the sensor has drifted greater than –10%.

ACTION - Check the integrity of all sensor connections, and ensure that the cable from the Model S4000C to the remote sensor is not damaged. If all sensor leads are connected properly, attempt to re-calibrate the unit. If calibration fails, replace the sensor and re-calibrate.

F5 UnusedF6 Low Supply VoltageThis fault occurs if the supply voltage at the S4000C

drops below +18.5VDC.ACTION - Ensure that the supply voltage is at least

+20VDC at the Model S4000C.

F7 EEPROM Verification FailureThis fault occurs when an attempt to verify the

setup/calibration parameters just written to theEEPROM memory fails.ACTION - The unit must be returned to the factory or

authorized service center for repair.

F8 Failure to Complete SetupThis fault occurs if the unit is left in setup mode for more

than 6 minutes.ACTION - Exit setup mode. Enter setup mode again if it is

necessary to change any user selectable options.

F9 Gas Check Period ExceededIf the Model S4000C is left in the gas check mode for

more than six minutes without a Test Gas being applied or if test gas is left on the gas check mode for more than 6 minutes, this fault will occur.

ACTION - Place the magnet over the GM Logo on the cover to return the unit to normal operation.

F10 Switch ErrorThis fault occurs if the remote reset, remote calibrate, or

the magnetic switch are closed for more than two minutes.

ACTION – Check the wiring on the remote reset and remote calibrate switches. Once the short circuit is cleared, the unit will return to normal operation. If the magnetic switch is shorted, the unit must be returned to the factory or authorized service center for service

Selamat Suriyadi MTT-14 instrument

Calibration of General MonitorsCalibration may be carried out as follows :1. Ensure that the instrument is no combustible gas present at the sensor. 2. Place the magnet on the General Monitors Logo on the Nameplate. wait until “ - - -” for 5 seconds Remove the magnet.The sensor will then display “AC”.3. Use Portable Purge calibrator with flow rate 300-400ml/min to apply gas at the required concentration level. When the instrument detect the gas it will display “CP”. Wait a seconds When the display become “CC”, and then remove the calibration gas.4.as the remaining gas in the sensor disperses, the sensor will exit Calibration mode and return to normal operation. The display should read “0”.