The HMGA is a multi-gas analyser originally designed for a customer working in the pneumaticcaisson and mining industry. HMGA, which means Hyperbaric Monitoring Gas Analyser, was designed to be used where there is a risk of asphyxiation or contaminated breathing air in subterranean work sites or hyperbaric environments.  

Underground construction is common practice in Japan especially in developing transport links, but also in the construction of building foundations, extraction of metals and mining for minerals and oils.

Sometimes construction can expose gases previously trapped underground. These gases can be toxic and can cause significant health problems if construction workers are exposed. If gas is encountered, the gas’s properties must be evaluated instantly to avoid any dangerous risks to health or even a life threatening environment.

Releasing these toxic gases can also unintentionally create an explosive environment, as the gases can react with each other, or the atmosphere.

Analox’s HMGA provides constant monitoring of five gases simultaeneaously O2, CO2, CO, CH4 and H2S and logs data for each sensor for 90 days providing full traceability.

Audible and visual alarms are displayed and announced on a PLC which takes in a data feed, provided via 4-20mA output. Custom produced software displays the levels of gas which are monitored.

The HMGA is installed on a caisson working site in Japan and is monitored from the main operational office. The unit draws gas samples from the caisson, which is approximately 40 meters deep, via sample lines which use natural pressure, helped by pumps. The gas is then analysed, reporting an accurate level and exhausted via an external outlet to the open atmosphere.

Key features

• Multi-gas analyser suitable for hyperbaric caisson applications
• Live data readings via Modbus comms
• Data logging
• Touch Screen
• Audible & Visual Alarms
• Remote monitoring up to 150m sample line (not included)
• Pressure sensor compensation (0-10 BarG)