RH350 Datasheet, PDF (3/6 Pages) Extech Instruments Corporation. – SuperHeat Psychrometer

Operation
Open the Protective Sensor Cap
Twist the protective sensor cap, located at the top of the
meter, counter-clockwise a quarter of a turn to expose the
sensors.
Turn Power ON or OFF
Press the [ON/OFF] button to turn power on or off. The
meter will perform a short self-test when turned on.
Taking measurements
1. Hold the probe in the area to be tested.
2. Allow adequate time for readings to stabilize.
3. The Relative Humidity measurement appears in the right display along with the date
and time.
4. Air Temperature appears in the top left display.
5. Wet Bulb is in the lower left display.
6. Pressing the [T1T/DPSEL] button toggles the top left display between Air temperature,
T1 temperature, Air-T1, and DP (Dew Point).
7. Pressing the [T2▲WB] button toggles the lower left display between WB (Wet Bulb),
T1-T2, T2, and T1-DP (Dew Point).
Selecting temperature units of measure (C/F)
When the meter is off, press and hold the [ON/OFFSET] button for more than one second to
enter setup mode. Momentarily press the [T1T/DPSEL] button until “unit” appears in the
display. Press the [MEM] button to toggle between C or F. Press the [T2▲WB] button to
confirm the setting and return to normal operation.
Setting the Date/Time (24 hour clock)
When the meter is off, press and hold the [ON/OFFSET] button for more than one second to
enter setup mode. Press the [T1T/DPSEL] button to select Year, Month, Day, Hour and Minute
in sequence. Press the [MEM] button to change the settings. After the Minute setting is
complete, press the [T2▲WB] button to confirm the date/time setting and return to normal
operation.
Data Hold
Press the [RECHOLD] button momentarily to freeze the displayed reading. The 'HLD' icon will
appear on the upper right-hand side of the display. Press the [RECHOLD] button again to
return to normal operation.
Minimum (MN) Maximum (MX) Average (AVG) Function
The MIN/MAX/Average mode allows the user to view only the lowest (MN), highest (MX) or
average readings. Press the [Mⁱⁿ/AVRST] button once and MN appears on the display. The
display is now showing the lowest humidity and temperature readings in memory. Press the
[Mⁱⁿ/AVRST] button again and MX appears on the display. The display is now showing the
maximum humidity and temperature readings in memory. Press the [Mⁱⁿ/AVRST] button again
to display the average (AVG) readings in memory. To exit the MIN/MAX/AVG mode, press
the [Mⁱⁿ/AVRST] button. To clear the current min/max/avg readings in memory, press and hold
the [Mⁱⁿ/AVRST] button for more than two seconds.
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RH350/355 V2.1 8/08