Velleman AVM52ERT Bedienungsanleitung Seite 3

Keep the connection cables separate when connecting them. The result of the measurement is
affected by the induction of current or voltage when the cables are touching or entangled.
Measurement errors may result if the resistance of the auxiliary earth bars exceeds 2KΩ. Be
careful, therefore, when you put the auxiliary earth bars P1 and C1 in the damp earth. Also
check the connection of the cables with the terminals.
2) Measuring the Earth Voltage of the Earthed Equipment under Test
Press the AC V button. The earth voltage is indicated on the V scale. The earth resistance
measurement may be inaccurate if the earth voltage > 5V. Turn off the power source of the
tested device or reduce the earth voltage to avoid this problem.
Note : The measurement is not influenced if the x1Ω, x10Ω or x100Ω button is in the pressed-
down position.
3) Checking Battery Voltage & Cable Connection
Both battery strength and the cable connections can be tested when the BATT.CHECK button is
placed in the pressed-down position :
a) Battery Voltage
The battery voltage is sufficient when the needle stays in the GOOD zone of the scale. If not,
replace the batteries (see "5. Battery Replacement" on p. 5).
b) Cable Connection
The OK lamp lights up if the cables of terminals P and C are connected properly and if the earth
resistance of the auxiliary earth bars falls within the limits you have determined. If the lamp does
not come on : check the connection of the cables with terminals P and C or reduce the earth
resistance of the auxiliary earth bars to an acceptable level by moistened the ground with water
or moving the earth bars.
Short the alligator clips at the end of the yellow and red wires to check them for damage.
Note that you can check the battery voltage without connecting any cables. Simply press the
BATT.CHECK button once. The OK lamp does not come on.
4) Measuring Earth Resistance
Press one of the range buttons x 1Ω, x 10Ω or 100Ω. Press the MEAS. button next. Multiply the
reading by 10 for the x 10Ω-range or by 100 for the100Ω-range.
The OK lamp is ON when the instrument is working normally. If the lamp is not lit, this indicates
that normal operation is made impossible by an excessive earth resistance across terminals C
and E. Verify again that there is no contact between the cables and recheck the earth
resistance of the auxiliary earth bars according to the principles outlined in "3) Checking
Battery Voltage & Cable Connection" above. Despite all previous checks, it is still possible for
the OK lamp to stay off and for the needle to exceed the upper limit value. This can be due to
several things : the tested device may not be functioning properly, its cables may be damaged
or the green connection cable may be damaged.
AVM52ERT 3 VELLEMAN