User Manual

RH401 V1.4 09/04

Calibration

The following verification and calibration procedures require a humidity chamber.

RH Accuracy Verification

Checking the 33% or 75% RH Calibration

1. Insert the meter into a chamber set to 33% or 75%.

2. Check the reading after 10 minutes

3. Verify that the reading is within the accuracy specification.

RH Calibration (33% and 75%)

This two point calibration takes approximately three hours to complete.

33% Calibration

1. Turn off the meter and insert it into a chamber set to 33%.

2. Allow the meter one hour to stabilize.

3. Hold down the and keys and then press the

key to turn the unit on.

4. “32.8” (reading may vary depending on temperature) will flash on the display. After

30 minutes, the flashing will stop to indicate that the 33% calibration is complete.

75% Calibration

1. Insert the meter into a chamber set to 75%.

2. Allow the meter one hour to stabilize.

3. From a steady “32.8” display press the button to enter the 75% calibration

mode.

4. “75.2” (reading may vary depending on temperature) will flash on the display. After

30 minutes, the flashing will stop to indicate that the 75% calibration is complete

and the calibration data has been saved to memory.

5. The screen will return to the normal display. Calibration is now complete.