THM420 Performance Verification
Handheld and Benchtop Instruments Basic Service
9
Table 9: DC Voltage Accuracy
Readout Limits
THM420 Range DC Voltage Source Minimum Maximum
400m V 300.0 mV 298.9 mV 301.1 mV
4 V 3.000 V 2.989 V 3.011 V
40 V 30.00 V 29.89 V 30.11 V
400 V 300.0 V 298.9 V 301.1 V
850 V 450 V 447 V 453 V
6. Disable the voltage source output.
7. Do not disconnect the test setup.
The following check verifies AC voltage measurement accuracy.
1. Set the THM420 DC/AC button to ACV.
2. Configure the voltage source to output AC.
3. Set the controls of the THM420 and the voltage source to each of the values
listed in Table 10; then verify that the THM420 readout remains within the
readout limits.
Table 10: AC Voltage Accuracy
AC Voltage Source Readout Limits
THM420 Range Voltage Frequency Minimum Maximum
400 mV 300.0 mV 1 kHz 295.0 mV 305.0 mV
4 V 3.000 V 50 Hz 2.965 V 3.035 V
40 V 30.00 V 1 kHz 29.50 V 30.50 V
400 V 300.0 V 1 kHz 295.0 V 305.0 V
600 V 450 V 1 kHz 438 V 462 V
4. Disable the voltage source output.
5. Disconnect the test setup.
AC Voltage