Chapter II
5000-count portable digital multimeter, with current input
16
∗
When the multimeter is linked to measurement circuits, do not touch unused
terminals.
∗
When the scale of the value to be measured is unknown, check that the scale initially
set on the multimeter is the highest possible or, wherever possible, choose the
autoranging mode.
∗
Before changing functions, disconnect the test leads from the circuit under test.
∗
In TV repair work, or when carrying out measurements on power switching circuits,
remember that high amplitude voltage pulses at the test points can damage the
multimeter. Use of a TV filter will attenuate any such pulses.
∗
Never perform resistance or continuty measurements on live circuits.
1.1.3. Symbols
Symbols used in this manual and on the instrument :
CAUTION
:
Refer to the instruction manual.
Incorrect use may result in damage to the device or its components.
DANGER
:
High voltage, risk of electric shock.
Earth
1.1.4. Instructions
∗
Before opening the instrument, always disconnect from all sources of electric
current and make sure not to be loaded with static electricity, which may destroy
internal components.
∗
Fuses must be replaced with fuses of the same rating and type.
∗
Any adjustment, maintenance or repair work carried out on the multimeter while it
is live should be carried out only by appropriately qualified personnel, after
having taken into account the instructions in this present manual.
A "
qualified person
" is one who is familiar with the installation, construction and
operation of the equipment and the hazards involved. He is trained and
authorized to energize, de-energize circuits and equipment in accordance with
established practices.
∗
When the instrument is open, remember that some internal capacitors can retain
a dangerous potential even after the instrument is powered down.
∗
If any faults or abnormalities are observed, take the instrument out of service and
ensure that it cannot be used until it has been checked out.
∗
It is recommended to remove the battery from the instrument if not used.
1.2.
Protection devices
This instrument is fitted with various protection devices :
∗
Varistor protection for limiting transients of over 1100 V at the V
Ω
terminal,
particularly 6 kV pulse streams as defined in French standard IEEE 587.
∗
A PTC (positive temperature coefficient) resistor protects against permanent
overvoltages of up to 600 V during resistance, capacitance, continuity and diode
test measurements. This protection is reset automatically after overload.
