Chapter II
MX 406B
12
3.2.
Continuity test
A current is generated through the resistor to be measured. The voltage drop measured at
its terminals is used to deduce its value.
Measurements must only be made on parts of installations or instruments that are out of
voltage.
The measurement is automatic when pressing the probe push button.
•
Measurement range :
0 to 10
Ω
You will hear a beeper for resistances of 2
Ω
, or less.
(Accuracy : -0
Ω
/ +0.5
Ω
)
•
Measurement current :
> 200 mA for R < 3
•
Input protection :
up to 440 V
AC
by CTP + MOSFET
•
Voltage at no load :
5 V
•
Accuracy :
class 10 over the entire scale
3.3.
Insulation measurement at 50 V, 250 V or 500 V
High voltage is generated at the terminals of the resistor to be measured. The voltage drop
measured at the terminals of a known internal resistor in series with the resistor to be
measured is used to deduce the value of the resistor.
Tests should only be carried out on circuits out of voltage (the mains light on the instrument
scale must be off after disconnecting the test leads and before pressing the probe push
button).
Connect the circuit to be measured to the instrument terminals, before starting the
measurement.
Measurement results may be distorted by the impedances of additional circuits connected in
parallel or by transient currents.
After a measurement, the high voltage present on the device under test discharges through
the leads and the instrument if the switch is set to V
position.
•
Measurement range :
200 k
Ω
to 200 M
Ω
at 250 V and 500 V
10 k
Ω
to 20 M
Ω
at 50 V
•
Measurement current : > 1 mA for R < 50 k
Ω
at 50 V
> 1 mA for R < 250 k
Ω
at 250 V
1 mA for R < 500 k
Ω
at 500 V
•
Protection of inputs :
up to 600 V
AC
•
No load voltages :
60 V
DC
on the 50 V range
320 V
DC
on the 250 V range
650 V
DC
on the 500 V range
•
Accuracy :
according to EN 61557
