- LEL Combustible Gas Analyzer with 0-100% or 0-4% of LEL
- Designed for Combustible Gases including Hydrogen Sulfide
- Gas Sampling for Vessels or General Safety with Wall Mount
- Explosion-Proof Enclosure
- Non-Intrusive Calibration
- Local Digital Display
- 4-20 mA Analog Output
- 2 Configurable High/Low Relays
- Long Life LEL Catalytic Sensor Average, 5-6 years
The ST-48 LEL gas detector is housed in a NEMA 4 Explosion Proof Enclosure and is available for hydrogen sulfide (H2S). Capable of monitoring the percentage of LEL combustible gas, the ST-48 is a perfect monitoring solution for providing worker protection in natural gas locations, paper mills, wastewater treatment facilities, the oil and gas industry, and other areas requiring hazardous monitoring for hydrogen sulfide.
The instrument’s fault supervision circuitry continuously monitors for failed sensor cell and communication. Our sensor cell operation is continuously supervised 24/7, and when used with distributive control systems or PLCs, the monitor provides immediate fault identification.
| Sampling Method |
Diffusion Cell |
| Gases Detected¹ |
Hydrogen Sulfide (H2S)
Ethanol (C2H5OH)
Ethane (C2H6)
Ethyl Alcohol (C2H5OH)
Ethylene (C2H4)
Isopropyl alcohol (IPA)
Methyl Alcohol (MeOH) |
| Accuracy |
± 1 % of Reading |
| Operating Temperature |
-32 to +50 ºC
-25 to +122 ºF |
| Display |
3 1/2″ Digit LCD Digital Display |
| Sensor Type |
LEL Catalytic Bead |
| Sensor Life |
2 to 5 years under Normal Conditions |
| Signal Outputs |
2 alarm relays, 4-20 mA analog output, and fault relay |
| Power Requirements |
24 VDC
95 mA |
| Width |
5.12 in
130.05 mm |
| Height |
5.0 in
127 mm |
| Depth |
8.0 in
203.2 mm |
| Weight |
4.7 lb
2.1kg |
| Enclosure |
NEMA 4 Explosion Proof Suitable for Class 1, Group B, C, & D |
1 Contact PureAire for more gases
Self-Supervised Operation
The PureAire ST-48 Hydrogen Sulfide Combustible Gas Monitor incorporates sophisticated electronics that, when used in conjunction with distributive control systems or PLCs enable you to quickly identify and correct major system faults. These enhanced self-diagnostic capabilities include missing cell and broken transmitter wiring. Should a system error occur, the ST-48 Combustible Gas Monitor outputs a 4-20 mA signal to remote alarm/control systems to immediately alert control room personnel.
