Which gas in the MultiRAE 6-gas configuration has a low alarm of 5 ppm and a high alarm of 10 ppm?

Which gas in the MultiRAE 6-gas configuration has a low alarm of 5 ppm and a high alarm of 10 ppm?

• A. HCN
• B. CO
• C. H2S
• D. O2

Answer: (A)

Alarm setpoints on a gas detector are chosen to reflect how hazardous a gas is and how quickly warning is needed. Hydrogen cyanide is extremely toxic even at very low concentrations, so detectors often use ppm-level thresholds like a low alarm around 5 ppm and a high alarm around 10 ppm to give rapid warning. That small, tight range fits HCN’s risk profile, helping users respond before exposure becomes dangerous. Other gases in this mix are typically configured differently: carbon monoxide alarms are usually set higher in the tens or hundreds of ppm because CO’s hazard builds more gradually, and oxygen is measured as percent by volume rather than ppm, with alarms expressed as a percentage of O2. Hydrogen sulfide commonly has alarm values in the tens of ppm, not in a tight 5–10 ppm range. So the configuration with 5 ppm and 10 ppm alarms corresponds to hydrogen cyanide.

Alarm setpoints on a gas detector are chosen to reflect how hazardous a gas is and how quickly warning is needed. Hydrogen cyanide is extremely toxic even at very low concentrations, so detectors often use ppm-level thresholds like a low alarm around 5 ppm and a high alarm around 10 ppm to give rapid warning. That small, tight range fits HCN’s risk profile, helping users respond before exposure becomes dangerous. Other gases in this mix are typically configured differently: carbon monoxide alarms are usually set higher in the tens or hundreds of ppm because CO’s hazard builds more gradually, and oxygen is measured as percent by volume rather than ppm, with alarms expressed as a percentage of O2. Hydrogen sulfide commonly has alarm values in the tens of ppm, not in a tight 5–10 ppm range. So the configuration with 5 ppm and 10 ppm alarms corresponds to hydrogen cyanide.