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Measurement Categories
These definitions were derived from the international safety standard for insulation coordination as it
applies to measurement, control, and laboratory equipment. These measurement categories are explained
in more detail by the International Electrotechnical Commission; refer to either of their publications: IEC
61010-1 or IEC 60664.
Measurement Category II
Local level. Appliances, portable equipment, and the circuits they are plugged into. Some examples
include light fixtures, televisions, and long branch circuits.
Measurement Category III
Distribution level. Permanently installed machines and the circuits they are hard-wired to. Some examples
include conveyor systems and the main circuit breaker panels of a building's electrical system.
Measurement Category IV
Primary supply level. Overhead lines and other cable systems. Some examples include cables, meters,
transformers, and other exterior equipment owned by the power utility.
Maintenance
Electric shock hazard:
Before opening the case, remove the test leads from the circuit and shut off the unit.
Failure to observe this warning could result in severe injury or death.
Replacing the Batteries
1. Disconnect the unit from the circuit.
Turn the unit OFF.
2. Remove the two screws from the
battery access door and remove it.
3. Replace the batteries, making sure to
observe the polarity.
Cleaning and Storage
Periodically wipe the case with a damp
cloth and mild detergent; do not use
abrasives or solvents.
If the meter will not be used for periods
longer than 60 days, remove the batteries
and store them separately.
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