407412 Datasheet, PDF (6/8 Pages) Extech Instruments Corporation. – Hygro Thermo-Anemometer

RS-232 PC Interface
The RS-232 serial data port (3.5mm phono jack) is located at the top of the meter next to
the sensor input jack. The PC interface hardware is intended for use with the Extech Data
Acquisition software package, Part Number 407001 which includes Windows^TM 95 / 98 /
ME / NT / 2000 compatible software and PC interface cable. For more information, contact
Extech or refer to the 407001 User's Manual.
Auto Power Off feature
The Auto Power Off feature automatically turns the meter off after approximately 10
minutes. To defeat this feature, place the meter in Record mode by pressing the RECORD
key once (the REC icon will appear on the LCD). The meter will remain powered as long
as the meter is in the RECORD mode.
Battery Replacement
When it is time to replace the 9V battery, the low battery indicator (LBT) appears in the left-
hand corner of the LCD display. Note that reliable readings can be obtained for several
hours after the first appearance of the low battery indicator.
To replace the battery:
1. Remove the meter's protective rubber holster.
2. Open the battery compartment on the back of the meter using a small coin or a flat
blade screwdriver.
3. Replace the 9V battery, close the compartment, and replace the holster.
Relative Humidity and Temperature Calibration
1. Turn the meter on and select the Humidity mode (RH %) using the Function switch.
2. Use a temperature simulator or calibrator to apply 0.0 ºC to the meter and adjust VR3
for a display of 0.0 ºC.
3. Change the input to 25.0 ºC and adjust VR1 for a display of 25.0 ºC.
4. Change the input to 50.0 ºC and verify a display of 50.0 ºC. Readjust VR3 & VR1 if
necessary.
5. Connect the humidity probe to the unit and place the probe in a controlled 33% RH
environment. Let stabilize for a minimum of 30 minutes and adjust VR5 for a reading of
33.0% RH.
6. Place the probe in a 75% RH environment for a minimum of 30 minutes and adjust “R6
for a reading of 75.0% RH.
7. Verify that the temperature reading is within the published specifications. If not, perform
calibration steps 2 and 3, above, again.
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Model 407412 Version 2.1 July 2006