Operation Manual

Chapter II
18 Portable digital multimeters
Definition of installation categories :
•
CAT IV: Measurement category IV corresponds to measurements taken at the
source of low-voltage installations.
Example: power feeders
•
CAT III: Measurement category III corresponds to measurements on building
installations.
Example: industrial machinery or instrument power supplies
•
CAT II: Measurement category II corresponds to measurements taken on
circuits directly connected to low-voltage installations.
Example: household appliance and portable tool power supplies
• CAT I: Measurement category I corresponds to measurements taken on
circuits not directly connected to the network.
Example: protected electronic circuits
1.2.1. Before use
• Comply with environmental and storage conditions.
• For your safety, before using the leads, systematically check they are is in
perfect working condition.
1.2.2. During use
A
s a safety measure, use only suitable leads and accessories supplied
with the instrument or approved by the manufacturer.
• If the measurement category of the accessory is different from that of the
apparatus, the lowest category applies to the unit.
• Never exceed the protection limit values indicated in the specifications for
each type of measurement.
• Before changing the function, disconnect the measurement leads from the
circuit measured.
• Never measure resistances on a live circuit.
• When the instrument is connected to the measurement circuits, never touch an
unused terminal.
1.3. Safety features
• It is impossible to access the battery or fuse compartment without first
disconnecting the measurement leads.
• When measuring voltages greater than 30 V
DC or 60 VAC, the symbol
flashes on the display.
• When measuring voltages above 7 A, the sign blinks on the display and
an intermittent audible signal warns the user.
• When there is a persistent overload on following ranges, an intermittent buzzer
indicates the risk of electric shock : VLOW Z, VAC+DC, VDC, ADPDC, ADPAC+DC,
500 mADC (or 50 mADC : MX 24 and except MX 23), 500 mAAC+DC
(or 50 mAAC+DC : MX 24 and and except MX 23), 10 ADC, 10 AAC+DC
(except MX 23).