15
GT-55e • GT-85e
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 I
Signal level. Electronic and telecommunication equipment,
or parts thereof. Some examples include transient-
protected electronic circuits inside photocopiers and
modems.
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.
Statement of Conformity
Greenlee Textron Inc. is certified in accordance with ISO
9000 (2000) for our Quality Management Systems.
The instrument enclosed has been checked and/or
calibrated using equipment that is traceable to the National
Institute for Standards and Technology (NIST).
