Engineered Systems Magazine
Detector for hydrogen sulphide

Gas Detectors: Automatikprodukter

October 5, 2011

The new gas detector H2S from Automatikprodukter, Sweden is designed to protect people, equipment, and plants from risks associated with hydrogen sulphide (H2S). The unit features Modbus communications protocol to facilitate fieldbus communication.

Hydrogen sulphide is a toxic gas whose odour is usually described as similar to the odor from rotten eggs. At high concentrations, there occurs a paralysis of the sense of smell. It is therefore not possible to use smell to determine if an area is dangerous due to the presence of hydrogen sulphide.

Modbus is a proven communications protocol for the instrumentation that provides digital communication without disturbing the integrity of the analog output signal 0-10Vdc or 4-20mA. Modbus allows multiple variables, parameters, device configuration and diagnostics to be transferred digitally simultaneously with the analog signal.

The H2S gas detector is delivered in explosion-proof design, is ATEX-compliant and has CE marking. Gas concentration is displayed on an LED display. The unit are equipped with two analog outputs; has an option for two additional relay outputs and is equipped with electro-chemical elements, which are highly selective and unaffected by ammonia, alcohols, and other gases that are common in these plant environments.

The detector monitors H2S gas in parts per million (ppm) and provides status indication and is equipped with alarm outputs. The sensor is available in 0-50ppm, 0-100ppm or 0-200ppm to support a wide range of applications.