1. GAS DETECTOR
BY : SELAMAT SURIYADI

2. Content Of Presentation
Introduction
About Gas Detector
Conclusion

3. Characteristic of Combustible gases
Introduction
Characteristic of Combustible gases
15 % LEL
LEL
Gas to Air mixture
EXPLOSION
5 % GAS
100 % LEL
4 % GAS
80% LEL
3 % GAS
60 % LEL
LEAN
2 % GAS
40% LEL
1% GAS
20% LEL
0 % LEL
0 % GAS

4. Combustible Gas Detection
Two types of combustible gas detection are :
• Catalytic
• Infrared Absorption

5. Catalytic Combustible Gas
Hydocarbon
Oxidizes
Heat
Resistance
Platinum
Wheatstone
Bridge
Voltage
Catalytic Combustible Gas

6. INFRARED DETECTORS
REFERENCE RECEIVER
MEASURING RECEIVER
GAS
IR TRANSMITTER
RAY SEPARATOR

7. 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

8. Use to indicating of presence combustible gas.
CONCLUSION
Use to indicating of presence combustible gas.
Use for safety devices.

9. THANK YOU

10. Calibration of General Monitors
Calibration may be carried out as follows :
1. “ - - -”
2. “AC”
3. “CP” “CC
5. “0”.
Selamat Suriyadi MTT-14 instrument

11. Selamat Suriyadi MTT-14 instrument
GENERAL MONITORS
The 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

12. Selamat Suriyadi MTT-14 instrument
ESD LOGIC GAS DETECTOR IN EDG AREA FSZ-41
Gas Detection in EDG
Area FSZ-41
2oo3
Gas Detection in EDG
Area FSZ-41
2oo3
Level 1
Stop and inhibit starting of EDG
7-EDG-3160
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
Level 2
Close phase-4 plant air utility distr.
Selamat Suriyadi MTT-14 instrument

13. SPECIFICATION Type : Standard Industrial Hydrocarbon Sensor
Model : S4100C Part.N 31100, Eexem II T5,
Eexem II T4
Response Time : Typically 6-second time constant when exposed to 50% LEL of methane gas.
Electric Classification : NEC and CSA ,class I ,Division I ,group B, C and D

14. VOTING SYSTEM 2oo3 CONDITION INHIBIT FAULT DETECT 1 2 3 4 5 6 7 8
CONDITION
RESULT No
INHIBIT
FAULT
DETECT
TRIP
NO TRIP
GD 1
GD 2
GD 3
GD1 1 2 3 4 5 6 7 8

15. Selamat Suriyadi MTT-14 instrument
Gas detector location and tag numbering
There are 3 Gas Detectors,4 Heat Detectors and 2 Fire Detectors On EDG-1360 AREA FSZ-41
HD-9000
HD-9001
HD-9002
HD-9003
FD-9022
FD-9023
GD-9024 on H-6320
GD-9025 on P-6310A
GD-9026 on P-6310B
STANDART
Hazardous Area Standards EN50014, EN50019, EN50028
Code of Protection EExem II T5 (– 50°C to + 55°C)
EExem II T4 (– 50°C to + 70°C) Cable insulation rated to at least 110°C
IP Rating: IP66/67
Application: Combustible Gas Monitor
2.2 Functional
Measuring Range: 0-100% LEL
Measuring Resolution: 1% LEL
Over-range Indication: Display flashes for readings greater than 99% LEL, but
continues to display gas concentration up to 120% LEL.
Calibration Level: User selectable 25% - 90% LEL in 1% LEL increments
A1 Trip level: User selectable 10% - 60% LEL in 1% LEL increments
A1 Open Collector Output User selectable Energised/De-energised and Latching/Non-latching
A2 Trip level: User Selectable 10% - 60% LEL in 1% LEL increments
A2 Open Collector Output User selectable Energised/De-energised and Latching/Non-latching
Fault Open Collector Output Normally Energised
Analogue Output during Calibration User selectable 0.0 mA, 1.5 mA and 2.0 mA
Modbus Baud Rate User selectable 2400, 4800, 9600 and Baud
Modbus Format User selectable 1 / 2 stopbits, odd / even / no parity, 8 databits
Modbus Node Address User selectable ; Address 0 is recognised as broadcast mode
Repeatability, Short Term: ± 5% LEL over 1 hour
Repeatability, Long Term: ± 10% LEL over 3 months
Accuracy (Linearity) ± 5% LEL
Temperature Variation ± 10% LEL over Temperature Range (- 50°C to +70°C)
Pressure Variation: ± 10% LEL (950 mBar mBar)
Humidity Variation: ± 10% LEL (20% RH - 90% RH)
Power up Variation: < 3% LEL after 5 minutes
Response Time (input step) T50 < 10 seconds
2.3 Mechanical
Height excl. Sensor: 150mm (6”)
Height incl. Sensor: 200mm (8”)
Width: 150mm (6”)
Depth: 95mm (3.75”)
Weight including Sensor: 2.5kg (5.5lbs)
Mounting holes: 4 x 7 mm (0.28”) dia holes
Termination: EExe II Terminal Block
2.Installation
a) Density of Gases to be Monitored — Lighter-than-air vapors/gases tend to rise, and
heavier-than-air vapors/gases tend to settle.
12 ISA-RP12.13-Part II-1987
b) Air Movement — Air velocity and direction influence the dispersion of vapors/gases to
be monitored.
c) Potential Sources — The location and nature of the potential vapor/gas sources (e.g.,
pressure, amount, source temperature, and distance) need to be assessed.
d) Ambient Temperature — Reference Section 9.8.
e) Volatility — Liquids of lower volatility require detectors nearer the source.
f) Vibration — Reference Section 9.7.
g) Accessibility — Detector head locations should consider future maintenance and
calibration requirements.
h) Structural Arrangements — Structural arrangements (such as walls, troughs, or
partitions) could allow vapor/gas to accumulate.
i) Mechanical Damage and Contamination — Detectors should be installed in locations
to preclude mechanical damage from normal operations (e.g., cranes, traffic, exhausts,
and washdowns).
Voting system 2oo3
Selamat Suriyadi MTT-14 instrument

17. 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.
Selamat Suriyadi MTT-14 instrument

18. SPECIFICATIONS

19. 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.
Selamat Suriyadi MTT-14 instrument

20. F3 EEPROM Checksum Error
there are nine Fault conditions that are monitored by the microprocessor, as follows: F2 Failed to Complete Calibration
This 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 Error
This 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 Error
This 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.

21. F5 Unused
F6 Low Supply Voltage
This 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 Failure
This fault occurs when an attempt to verify the setup/calibration parameters just written to the
EEPROM memory fails.
ACTION - The unit must be returned to the factory or authorized service center for repair.
F8 Failure to Complete Setup
This 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.

22. F9 Gas Check Period Exceeded
If 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 Error
This 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

23. Selamat Suriyadi MTT-14 instrument
Calibration of General Monitors
Calibration 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 ml/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”.
Selamat Suriyadi MTT-14 instrument

24. WORK PERMIT White - Work Location Yellow - Operating authority
MAIN WORK PERMITS
COMPLEMENTATRY PERMITS
HOT WORK PERMIT
COLD WORK PERMIT
WORK PERMIT FORMS
Certificate
PERMITS FOR SPECIFIC WORK
Isolations
Electrical Safety Procedures
Gas testing
Entry into confined space
Lifting Operations
Hot Tapping
Excavations
Service Vessel Operations
Diving
Ionizing Radiations
White - Work Location
Yellow - Operating authority
Blue Control room
Pink Safety S/I