Velleman DVM1322 Mode D'emploi page 2

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.
DVM1322 2 VELLEMAN