Data Hold Mode; Max/Min Mode - Extech Instruments AN310-NIST User Manual

Relative Humidity, Wet Bulb, and Dew Point Measurements
The relative humidity sensor is built in to the center of the vane (rear of meter) and can be used to
measure relative humidity, dew point and wet bulb temperatures.
1. Press U/mode to switch to the %RH display if necessary. The measured humidity readings
will be displayed on the upper LCD digits.
2. Use the L/mode button to scroll through air temperature, dew point temperature, wet bulb
temperature, and air volume readings.
3. To measure the humidity using an offset reference value, please access the Setup mode and
input the offset value as described in the Setup mode section. The LCD will display the
measured value minus the offset value once the offset is programmed in the Setup mode.
Data Hold Mode
1. Press the HOLD button from the normal operating mode to freeze the current measurement.
2. The 'HOLD' icon will appear at the top of the LCD display.
3. Press HOLD again to return to normal operation. The 'HOLD' icon will switch OFF and the
meter will return to displaying readings in real time.
MAX/MIN Mode
The MAX‐MIN feature records the highest (MAX) and lowest (MIN) readings captured since the
MAX‐MIN mode was accessed.
1. Press and hold the MAX/MIN button for 2 seconds to begin displaying the lowest (minimum)
readings encountered since this mode was accessed. The 'MIN' icon will appear at the top of
the LCD display indicating that the readings shown are the lowest measured.
2. Press and hold the MAX/MIN button again for 2 seconds to display the maximum readings
encountered. The 'MAX' icon will appear on the LCD.
3. Press and hold this button again for 2 seconds to return to the normal mode of operation
(the 'MIN' and 'MAX' icons should switch OFF).
4. While viewing the MAX or MIN data, use the L/mode button to switch the display so that the
Air Volume MIN and MAX readings can be viewed also.
5. Press and hold MAX/MIN for 2 seconds to return to the normal operation mode.
Multi‐Point Average Mode
1. From the normal operating mode press the U/mode button for 2 seconds to enter Multi‐
Point Average mode (the AVG display icon and the associated black dot • will switch ON).
2. Press the HOLD button momentarily to record one reading. The upper display digits will
show the reading's memory location number and the lower display will show the measured
value. Press the HOLD button again to take and store another reading; the memory location
number will increment by one and the current reading will be stored in this new memory
location. The meter can store up to 19,999 points in memory.
3. Press U/mode momentarily to see the multi‐point mean (average) for all of the readings
recorded during the session (the '•AVG' display icon will flash during this process).
4. Press L/mode to view the average reading for the other available parameters.
5. Press U/mode momentarily to return to the normal operating mode.
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