Using The Resistance Testing Loop - LEM HEME GEO 15 Manuel D'utilisation

Using the resistance testing loop

3 Using the resistance testing loop
Using the resistance testing loop included in the scope of delivery, the correct func-
tion of the earth/ground loop tester can be verified. Prior to every proper measure-
ment, the testing loop can verify the functionality of the device and whether the
specified tolerances are being met or not. For example: The results of any meas-
urement can be invalidated through unforeseeable errors, sometimes requiring the
whole measurement to be repeated, which can be very time-consuming. It is rec-
ommended to use the resistance testing loop prior to every measurement. Test all
ranges that can be simulated with this loop.
Open clamping jaws. Ensure that the contact surfaces are clean and free of
dust, debris and other foreign substances.
Open and close the clamping jaws several times to obtain the best fit.
Turn on device and set the dial to Ω.
Do not attach to a conductor and do not open the clamping jaws at
this time and during selfcalibration.
For better accuracy, the earth/ground resistance tester conducts a selfcalibration
during start-up. The user must wait until the selfcalibration has been completed.
The following appears on the LCD screen during the selfcalibration process:
CAL7, CAL6, ..., CAL2, CAL1.
A beep signals that the device is ready for operation.
Attach the device to the resistance loop at the chosen resistance value. It is
recommenced to measure all values available on the resistance loop.
The measured resistance is shown on the LCD screen. It must both match the
value given on the resistance loop and comply with the specified tolerances.
Note: To achieve a better measuring performance:
Open and close clamping jaws several times before the device is turned on.
Do not attach to a conductor upon start-up.
Note: If the selfcalibration takes longer then expected:
The selfcalibration process has not been completed yet. The device will continue
with the calibration until the process is complete. Check the contact areas of the
jaw surfaces. If dust, debris or other foreign substances are present, the surfaces
must be cleaned.
- 6 -