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Description / Abstract:
These requirements cover electrical and electrically operated
indicating and recording instruments of the analog type that are
powered only from the measured parameter and are intended for
ordinary use in panel boards and the like.
These requirements cover direct-acting or indirect-acting
instruments and accessories that may contain electronic
devices.
These requirements cover instruments indicating quantities of
electrical analogs including all of the following:
a) Ammeters.
b) Voltmeters.
c) Wattmeters.
d) Varmeters (reactive volt-ampere meters).
e) Frequency meters.
f) Power-factor meters.
g) Synchroscopes.
These requirements cover instruments constructed for special
purposes such as, ultrasensitive d-c microammeters, high-resistance
voltmeters, thermo-milliammeters, thermal voltmeters of the
vacuum-couple type, and instruments with special and unusual
ranges.
These requirements cover analog instruments that may be
categorized according to use or principle of operation as
follows:
a) Use:
1) Panel Type, including edgewise.
2) Switchboard type, including edgewise.
b) Principle of operation:
1) Electrodynamics.
2) Permanent-magnet moving coil.
3) Moving iron.
4) Thermocouple.
5) Rectifier.
These requirements also cover auxiliary equipment and
accessories designed to be used with measuring instruments as
indicated in 1.1 – 1.5.
These requirements do not cover:
a) Indicating instruments provided with arrangements for curve
drawing, contact making, and the like that derive the power for the
functioning of these arrangements from an external source other
than the measured parameter.
b) Instruments that use active devices such as transistors,
electron tubes, and the like for amplifying the electrical quantity
measured, that require a power source other than the quantity
measured for operation. An example of this is a battery-powered
ohmmeter. This equipment is covered by the requirements for
electrical and electronic measuring and testing equipment, UL
1244.
Instruments covered by these requirements are intended for use
indoors or in sheltered (from the elements) locations, as follows:
a) Temperature – 5 – 40°C or 41 – 104°F; instruments may
occasionally be used for temporary or short periods at minus 10 –
plus 5°C or 14 – 41°F. b) Altitude – Up to 2200 meters (7218 feet).
c) Relative Humidity – Up to 80 percent.
These requirements do not cover certain other properties of the
instruments such as effectiveness, accuracy, or reliability.
Throughout this Standard the term ²instrument² applies to analog
indicating and recording instruments and their accessories as
described in 1.1 – 1.6.
A product that contains features, characteristics, components,
materials, or systems new or different from those covered by the
requirements in this Standard, and that involves a risk of fire,
electric shock, or injury to persons shall be evaluated using the
appropriate additional component and end-product requirements as
determined necessary to maintain the acceptable level of safety as
originally anticipated by the intent of this Standard. A product
whose features, characteristics, components, materials, or systems
conflict with specific requirements or provisions of this Standard
cannot be judged to comply with this Standard. Where considered
appropriate, revision of requirements shall be proposed and adopted
in conformance with the methods employed for development, revision,
and implementation of this Standard.