NOTES:
1.
If the meter is ON for < 15 minutes, the STEL value will be
the weighted average of readings taken since power on.
Similarly, for the TWA mode when the meter has been ON
for < 8 hours, the display only shows a weighted average of
the readings up to the moment.
2.
The GSM450 requires at least 5 minutes calculating STEL and
TWA. The display shows “----” during the first 5 minutes from
power ON.
3.
While in HOLD mode, the STEL and TWA values will continue to
update every 5 minutes.
4.
Hold, Record, and Recall functions are not operational while in
Min/Max/Avg mode.
5.
TWA and STEL will function only in CO
2
mode
6.
The unit of measure can be changed while in Min/Max mode.
Manual Data Recording
The GSM450 has 99 memory locations for which to store readings one
at a time.
1.
While in normal operating mode or hold mode, short press the
MEM/
button to store a reading. The REC icon flashes on the
display for approximately 3 seconds. The primary display briefly
shows the memory location.
2.
Each measurement parameter is saved, not just the currently
displayed parameter. (For example, when recording CO
readings, the CO
2
, %RH, and air temperature will also be
recorded).
3.
Short press the H/
button to freeze the readings on the
display before recording the data if the readings change too
quickly.
Note: The manual recording mode is not operational in Min/Max
mode.
