HT instruments M70 - Manual (Page 11)

M70
EN - 10
4.5. Lo
: CONTINUITY TEST ON EARTH, PROTECTIVE AND EQUALIZING
POTENTIAL CONDUCTORS
The measurement is performed with a test current higher than 200mA (R<5Ω) and open
circuit voltage ranging from 4 to 24V DC according IEC/EN 61557-4 and VDE 0413 part 4.
CAUTION
Before taking resistance measurements make sure that the circuit under test is
not powered and that eventual condensers are discharged. The measured
value is out of accuracy if an input voltage is present.
Fig. 6: Connection of the instrument’s terminals during Lo  test
1. Turn on the instrument
2. Press the arrow keys to select Lo 
3. Insert the black and red cables in the corresponding input terminals of the instrument
4. If the measuring cables being used
have not been calibrated, first calibrate
them as described in § 4.5.1
Resistance value
5. Position the test probes on the desired
points of the circuit under test (see Fig.
6)
6. GO
Press GO to perform the
measurement
7. + GO
Press LOCK and GO together to perform the measurement in
continuous mode, the symbol LOCK is displayed. Press GO
another time to stop the continuous mode measurement
8.
In lock mode the instrument emits an acoustic signal and the auto power off is
disabled