General Tools and Instruments CDM77535 - Manual (Page 5)

BACKLIGHT
Hold down (
) for more than 1 second to activate and cancel
backlight function.
MIN, MAX, STEL, TWA
Under normal mode, press (
) to see the minimum, maximum,
and weighted average readings. Each press of ( ) displays MIN,
MAX, STEL, and TWA in sequence and returns to normal mode.
In MIN and MAX modes, it shows the minimum and maximum
readings of CO
2
on main display and of AIR or DP or WB temperatures
and humidity on the lower displays. (Fig. 7)
In STEL and TWA modes, the main display shows the weighted
average of CO
2
readings for the past 15 minutes (STEL) and 8 hours
(TWA). The lower displays are the current AIR, DP/WB temperatures
and humidity. (Fig. 8)
NOTE:
1. If the meter is turned on for shorter than 15 minutes, the STEL
value will be the weighted average of readings taken since
power on. Same for TWA values appear before 8 hours.
2. It takes at least 5 minutes to calculate STEL and TWA. The
display shows “_ _ _” (Fig. 9) during the first 5 minutes from
power on.
3. While all readings are held unchanged, STEL and TWA will keep
updating every 5 minutes.
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