Logically, people assume the lower the gas detection alarm level, the safer the working environment, as the body will be exposed to less poisonous gas. However, this is not always the best option! If set too low, they can cause spurious alarms and unnecessary disruption. Worse still, these wolf cries have led to many incidents of detectors being ignored or switched off; with terrible results1.
Unique to T4, the TWA Resume function ensures toxic gas exposure is calculated accurately over an entire shift, even if T4 is switched off for a break or during travel to another site.
When most portable detectors are turned off, the algorithm that assesses TWA exposure assumes that it’s the end of the shift. When turned on again, these detectors act as if it is a new work shift, ignoring all previous measurements. The TWA Resume function however, provides the option to include previous measurements from within the correct time frame.