Velleman DVM1322 - Manual (Page 4)

DVM1322_v2 VELLEMAN 4
e) "MAX"-mode
Select the desired input (T1, T2 or T1-T2) and press the MAX-key. The thermometer will now record and update the
maximum value for the selected input. The "MAX"-symbol appears on the display. Press MAX again to exit the
"MAX"-mode.
Press HOLD while the device is in the "MAX"-mode to stop the readings and press HOLD again to resume them.
4. Offset Adjustment
The OFFSET controls are set by the manufacturer and allow for the variations found in standard thermocouples. Use
the OFFSET controls to obtain maximum accuracy for a particular thermocouple (or a pair of thermocouples) when
used to measure a known temperature.
Adjustment for T1- or T2-Measurements
(a) Connect the thermocouple to the T1-input connector and activate the thermometer by pushing ON/OFF. Press
ON/OFF and T2 if you wish to use the T2-input connector.
(b) Place the thermocouple in an environment with a known and stable temperature that is close to the temperature
you wish to measure and allow the readings to stabilise.
(c) Slowly adjust the OFFSET control that corresponds to the selected input until the temperature reading matches
the known temperature of the selected environment. Wait long enough in between adjustments as the device
needs some time to perfect its readings.
(d) Calibration of the device is now optimised for temperatures that approximate the temperature measured in (b).
Adjustment for T1-T2 Measurements
(a) Connect the thermocouples to the input connectors.
(b) Activate the thermometer and press T1-T2.
(c) Place both thermocouples in an environment with a known and stable temperature that is close to the
temperature you wish to measure and allow the readings to stabilise.
(d) Slowly adjust the OFFSET control for one of the thermocouples (but NOT for both) until the display reads "000".
Wait long enough in between adjustments as the device needs some time to perfect its readings.
(e) Calibration of the device is now optimised for the measurement of differential temperatures that approximate the
temperature measured in (c).
Reinstalling the OFFSET controls
Use the following procedure to reinstall the factory settings without having to recalibrate the device :
♦ Connect a thermocouple to the input to be adjusted.
♦ Place the thermocouple in an ice-water bath and allow the readings to stabilise.
♦ Slowly adjust the corresponding OFFSET control until the thermometer reads 0°C or 32°F.
5. Maintenance
WARNING : DISCONNECT ALL THERMOCOUPLES BEFORE REMOVING THE COVER IN ORDER TO AVOID
ELECTROSHOCKS.
Battery Replacement
Always use a 9V-battery (6LR61, IEC6F22). The
-symbol is displayed when the battery needs to be replaced.
Remove the three screws at the back of the device, remove the cover and replace the battery.