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).
14
1.800.561.8187
information@itm.com
www.
.com