RKI Instruments GX-94 - Manual (Page 25)

GX-94 Operator’s Manual Page 24
Short-Term Exposure Limit (STEL) Screen
The STEL function shows the average reading for H
2
S and CO during
the last 15 minutes. These values are not affected by the Lunch Break
function and are reset every time the unit is turned off.
Time-Weighted Average (TWA) Screen
The TWA function shows the average reading for toxic gases during the
last 8 hours. If 8 hours has not elapsed since the last time the STEL/
TWA was cleared, the average is still calculated over 8 hours, with the
missing time assigned a 0 value for readings.
When the Lunch Break RESUME option is selected during start-up, the
GX-94 will include the TWA from the last session.
STEL
H2S 0. 0 PPM
CO 0PPM
TWA
H2S 0. 0 PPM
CO 0PPM