EXTECH MG325 [14/18] Polarization index pi insulation testing

14 MG325-en-GB_v1.1 3/16

6.9.4 Polarization Index [PI] Insulation Testing

Read and understand all operations and safety information contained in the Insulation Resistance

measurement section above and the Safety section before continuing.

1. Connect the meter to the device under test as shown in the Insulation test section above.

2. Select the desired output test voltage using the rotary function switch.

3. Use the PI/DAR button to access the PI test mode.

4. The display will show the PI icon when the PI mode is successfully accessed.

5. The test times (10 minutes : 1 minute) will show on the lower right.

6. Press the TEST button to start the test.

7. During the test the auxiliary display digits show the test time in seconds, the voltage alert

flashes on the upper left, and the ‘test voltage alert’ LED illuminates.

8. The test will stop automatically after 10 minutes.

6.9.5 Comparator Utility

Read and understand all operations and safety information contained in the Insulation Resistance

and Continuity measurement sections and the Safety sections before continuing.

In Comparator mode the meter compares Insulation Resistance or Continuity measurements to a

preset resistance value and displays PASS (measured value greater than reference value) or

FAIL (measured value lower than reference value).

1. Connect the meter to the device under test as shown in the Insulation Resistance or

Continuity test sections above.

2. Press the COMP button momentarily and the COMP icon will appear on the lower left, next to

the comparison resistance value.

3. Press and hold the SET button until the SET icon is shown.

4. Use the

button to step to the COMP screen (see the SETUP mode section below for

more details on the SETUP mode).

5. Use the arrow buttons to step to the desired reference value.

6. Press

to confirm setting.

7. Press and hold the SET button to return to the test mode.

8. Press COMP momentarily and the COMP icon will appear.

9. Press the TEST button to start the test. If the measurement is greater than the reference then

the test passes and PASS will be displayed; if the measured value is lower than the reference

then the test fails and FAIL is displayed.

10. The Insulation Resistance comparator preset options are: 500k, 1M, 2M, 5M, 10M, 20M, 50M,

100M, 200m, and 500MΩ.

11. The Continuity comparator preset options are: 1, 2, 5, 10, and 20Ω.