Extech Instruments RH300, Руководство пользователя

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RH300-en-GB_v1.7 9/16 5
Calibration
The following verification and calibration procedures require the 33% and 75% RH reference bottles
which are supplied with the Model RH305 kit.
Accuracy Verification
Checking the 33% or 75% RH Calibration:
1. Insert meter’s sensor into the 33% or 75% salt reference bottle.
2. Check the reading after 10 minutes.
3. Verify that the reading is within the accuracy specification.
Relative Humidity Calibration (33% and 75%)
Calibration Preparation

Ensure that fresh batteries are installed in the meter.

Move the protective vent cap to the
Open
position.

Power the meter ON and set it to display dew point (
DP)
and wet bulb (
Wb)
in the lower display
area.
Calibration Procedure
1. Follow the Preparation steps above before continuing.
2. Power the meter OFF.
3. Insert the meter into a 33% salt bottle.
4. Leave the meter OFF for one hour (to stabilize).
5. After the meter has stabilized for one hour:

Press and hold the °C/°F button while powering the unit ON.

The unit enters calibration mode (32.8% flashes on the display).

The DP and Wb display areas show DP ---- Wb ----°C.
6. Once the 33% calibration is complete, the display stops flashing and a constant 32.8% is
displayed.
7. Allow the meter to remain ON and move it to the 75% salt bottle.
8. Allow the meter to remain for one hour in the 75% salt bottle to stabilize.
Important: Do NOT power the meter OFF while in the Calibration mode! Note that
AUTO POWER OFF is disabled while in the Calibration mode.
9. After one hour, press and hold the MN/MX button until
75.3%
begins flashing on the meter
display. The meter has now entered the 75.0% calibration stage.
10. After 30 minutes have elapsed, the meter will automatically exit the calibration mode and
return to the normal operating mode.
11. The Calibration is complete, turn power OFF.
Note: To exit from the calibration procedure before completion, press the
ON/OFF
button.
Note: If the salt at the bottom of the calibration bottles appears dry, the bottles should be replaced.
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