OPERATION OF TOXIRAE
2 - 8
2.4
Operations
In the normal operations, the ToxiRAE Pocket PID Unit
displays six different readings: Instantaneous gas
concentration, TWA, STEL, Peak in ppm, battery voltage
in volt and run time in hours and minutes. In addition,
there are two more displays to enable or disable
datalogging operation (only in datalog version of PGM-
30D) and to communicate with a PC. Here is a brief
explanation of each display:
1) The
instantaneous
reading is the actual gas
concentration in parts per million (ppm). The reading is
updated once per second and is shown as "nn.n ppm" in the
LCD display.
2) The
TWA
reading is the accumulated reading of the gas
concentration divided by 8 hours since the unit was turned
on. The reading is updated once a minute and is shown as
"TWA nn.n" in the LCD display.
2) The
STEL
reading is the last 15 minute average reading
of the gas concentration. The reading is updated once per
minute and is shown as "STEL nn.n" in the LCD display,
for the first 15 minutes “STEL****” will be displayed.
4) The
P
eak
reading is the maximum reading of the gas
concentration since the unit was turned on. The reading is
updated at one second intervals and is shown as "Peak
nn.n" in the LCD display.