If you’ve ever worked around a confined space, you’ve probably seen or heard about an incident involving missed alarms. Perhaps the attendant set the gas monitor on the ground and stepped away to sign paperwork or respond to a radio call. Because of noise from nearby machinery, the attendant completely failed to notice that the gas monitor went into alarm, and he could not see it because it was on the ground. Powerful alarms and a highly visible design are two important features to consider when choosing an area monitor for confined space work.
When handheld monitors end up on the ground, tied to a railing, or left in other vulnerable positions, it’s more likely that the pump and tube can be damaged or stop working. The rugged, upright design of an area monitor is beneficial because it’s less likely to become damaged when left sitting in or near a confined space. The readings on handheld monitors are also difficult to see if the attendant is more than a couple of feet from the instrument. An area monitor with an extra-large display can be seen from a distance, which is helpful for attendants who are standing in another area or watching multiple monitors at once. On the newest area monitors, alarm action messages can be programmed to correspond with rising gas levels within the confined space to provide early warning when conditions are starting to become unsafe. If the monitor is inside the space with the entrant, he would see “VENTILATE” instead of just “CO 35 PPM” and a flashing low alarm icon. Likewise, for a high alarm inside the confined space, the entrant would see the gas reading of “H2S 20.0 PPM” and the alarm action message “EVACUATE.” These highly visible messages give the entrant and attendant time to respond appropriately, and with clear direction.
The next time you’re working in a high noise or low visibility environment, take stock of your gas detection equipment. Does it blend into the surroundings or stand out and provide clear direction?