TESTO 770 - Carrying Out a Measurement; Preparation for Measurement; Current Measurement

7 Carrying out a measurement
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7 Carrying out a measurement
7.1 Preparing for measurement
Prior to every measurement, please ensure that the instrument is in perfect
condion:
• For example, keep an eye out for broken housing or leaking baeries.
• Always carry out a funcon test before using the instrument, see below.
• Check that the instrument is funconing perfectly (for example at a known
voltage source) before and aer every test.
• If the safety of the user cannot be guaranteed, the instrument must be
switched o and secured to prevent unintenonal usage.
When connecng the test leads to the test object, always connect the
common test lead (COM) to the test object rst of all. When
disconnecng the test leads, always disconnect the +/- phase test lead
rst of all.
7.2 Current measurement
WARNING
Serious risk of injury to the user and/or destrucon of the instrument while
measuring current.
> Measuring circuit must be de-energized.
The measuring instrument may only be used in circuits up to a
maximum voltage of of 600 V (testo 770-1/-2/-3 (0590 7703)) /
1000 V (testo 770-3 (0590 3770)). The nominal cross-secon of the
connecon cable must be taken into account in order to ensure safe
connecon (e.g. via crocodile clips).
Strong RF interference and / or open leads when measuring A AC may
result in unstable display readings.
For the A DC and μA DC measurement always zero the instrument with
[ ] before measuring.