EXTECH EX380396 [9/17] Dielectric absorption ratio dar

380395/380396 -EU-EN-V1.2-4/12

Dielectric Absorption Ratio (DAR)

The dielectric absorption test calculates the ratio of the resistance measurement after one minute to

the resistance measurement after 30 seconds: Results are determined by the type, age and

condition of the insulation material tested. Established standards and test procedures should be

used to establish pass/fail criteria for each application.

Dielectric Absorption Ratio = Resistance after 1 minute / Resistance after 30 seconds

1. Connect the Black Earth test lead to the Earth connector and the Red test lead to the LINE and

COM connectors.

2. Connect the test leads to the device under test.

3. Set the Function Selector switch to the desired insulation test voltage.

4. Use the PI/DAR button to select the Dielectric Absorption Ratio function (DAR) for TIME1.

5. Press and hold the PRESS TO TEST button and turn it clockwise to the LOCK position. The

beeper will sound during the test.

6. When the test has completed, the LCD will display PASS if the Dielectric Absorption Ratio is

greater than 1. FAIL will be displayed if the Dielectric Absorption Ratio is below 1.

7. Keep the test leads connected to the device under test and release the PRESS TO TEST

button. The circuit will discharge through the meter. While the circuit is discharging, the

icon will flash.

8. Press the STOP button to clear the results

Insulation Resistance Measurement Considerations

The Resistance of an insulator is determined by applying a test voltage to the insulator and then

measuring the subsequent current flow.

Notes:

 The insulation resistance of a device may not be stable therefore the readings supplied by

the meter may vary.

 An audible beep will be heard while a test is in progress, this is normal.

 Measurements taken on a capacitive load may take some time to complete.

 Insulation Resistance tests output a positive (+) voltage from the Earth terminal and a

negative (-) voltage from the Line terminal.