HT instruments M71 - Manual (Page 15)

M71
EN – 14
6.
CAL
After pressing the CAL key the instrument carries out zero setting of cables'
resistance (this procedure takes approx. 30sec). Cables with a resistance up
to 0.3
Ω can be calibrated.
CAUTION
When “Measuring…” is displayed the instrument is effecting measurement.
During this phase do not disconnect test leads from the instrument.
7. At the end of the test the measured value
is stored by the instrument and used as
OFFSET (that is to say deduced from all
EARTH 3W measurements) for all
subsequent measurements till a further
zero setting. The instrument emits a
double sound tone indicating the positive
outcome for zero setting and displays
again the initial screen by the symbol
CAL.
Symbol CAL:
indicates that the
instrument was
calibrated; this
symbol is
displayed for each
subsequent
measurement
even though the
instrument is
switched off and
on again.
8. If during cables' zero setting the value
measured is higher than 0.3 Ω the
instrument interrupts such setting
procedure, removes the previous offset
value and does not display the symbol
CAL until a cables' zero setting is
successfully carried. out The instrument
emits a long sound tone indicating the
unsuccessful setting outcome and has
been displaying a screen similar to the
side one for about 2 seconds, then it
displays a default screen.
Note: this procedure can be used also to
cancel the last value stored for cables'
zero setting.