Omega HHM31 User Manual page 15

HHM31 CALIBRATION PROCEDURE
Note: Only qualified technicians who have access to the items, as following should
perform the following calibration procedure.
Equipments: The class of calibrator had better 10 times greater than the measured meter.
DCV Calibration
Set the function /range to the DC 200mV，then apply 190.0mV to the V-W and
COM input jacks.
Adjust R41 until display reads 1900±1dgt then disconnect the source from the
measured meter.
DCA Calibration
Set the function /range to the 10A, set the output of the current calibrator for
1.9A, and connect it the 10A and COM jacks.
Adjust the shunt resistor until the display reads 1.9A, if the reading over 1.9A
then add solder onto the shunt resistor, below 1.9A then cut CuMn Shunt Resistor
slightly with diagonal cutters or shave away some of solder from the Shunt.
Temperature Calibration
Insert the K type thermocouple to the female connector, and the other side of
this probe to Temperature Calibrator. We must allow the K type to stabilize for at
least 1 minute and make sure "+" and "-" polarity is right position.
1. Set the range to the T1/0.1°C, and then apply 0°C to T1 input (T2 input open)
adjust R845 and R846 (fine adj.) until LCD reading reads 0.0±0.1°C.
2. Set the range to the T1/0.1°F, and then apply 0°F to T1 input (T2 input open)
adjust R804 until LCD reading reads 0.0±0.1°F.
3. Set the range to the T1/0.1°F, and then apply 165°F to T1 input (T2 input
open) adjust R891 until LCD reading reads 165.0±0.1°F.
4. Set the range to the T1/1°F, and then apply 1832°F to T1 input (T2 input
open) adjust R824 until LCD reading reads 1832±1°F.
5. Set the range to the T1/1°C, and then apply 1000°C to T1 input (T2 input
open) adjust R806 until LCD reading reads 1000±0°C.
6. Set the range to the T2/0.1°C, and then Apply 0°C to T2 input (T1 input open)
adjust R82 and R83 (fine adj.) until LCD reading reads 0.0±0.1°C.
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