MSA S4000TH H2S Gas Detector

MSA S4000TH H2S Gas Detector


The S4000TH Intelligent Gas Sensor is a microprocessor-based transmitter designed for use with General Monitors' thin film metal oxide semiconductor (TFMOS) sensors to detect H2S gas.


The S4000TH Intelligent Gas Sensor features one-person calibration and can be virtually self-calibrating by simply activating a magnetic switch and dispensing gas. It detects hydrogen sulphide in levels of 0-20 ppm, 0-50 ppm or 0-100 parts per million (ppm) over a wide temperature range.

This product is available in several options and therefore the price is on request. For more information and pricing, please contact us at


  • Meets the stringent ISA S92.0.01, Part 1, 1998 performance standard set by ISA and approved by FM
  • Event logging stores fault, gas check, calibration and alarm event history
  • HART and Modbus communication provides full status and control capabilities in the control room
  • Industry standard 4-20mA output for remote alarm and fault indication
  • Warning, alarm and fault relays provide local alarm capability
  • Calibration, calibration check, setting mode simplifies operation and maintenance
  • Remaining sensor life indication reduces downtime by providing an estimate of remaining sensor life

H2S Sensors and accessories

General Monitors hydrogen sulphide (H2S) sensors are solid state devices, designed and manufactured for long life and fast response. They are selective for H2S and remain unaffected by high concentrations of other substances such as hydrogen, sulphur dioxide and gasoline vapours, which are often present in installations processing sour gas and crude oil. A high tolerance for a wide temperature and humidity range allows these sensors to operate in harsh environments, as does their ability to withstand exposure to high H2S concentrations for short periods of time. See the available sensors and related accessories in the attached datasheet.

More Information

More Information
Repeatability ±2 ppm or 10% of the applied gas, whichever is larger
Measuring range 0-20 ppm, 0-50 ppm, 0-100 ppm
Operating storage temperature -50°C to 85°C (-58°F to 185°F)
Operating humidity range 0% to 95% RH, non-condensing
Dimensions (l x w x h) 161 x 104 x 86 mm
Weight 2.5 kg
Input power 24 VDC nominal, 20 to 36 VDC, 350 mA max.
Relay ratings 8A @ 250 VAC / 8A @ 30 VDC res. max. (3x) SPDT
EMC protection Complies with EN 50270, EN 61000-6-4
Baud rate 2400, 4800, 9600, or 19200 BPS