84

Glossary

Glossary of Terms

MI

Moving iron, also called ‘iron vane’ in the North American market for measuring AC amps and volts.

MC

Moving coil for measuring DC amps and volts.

Taut band suspension

A meter movement held under tension, usually on a ligament.

movement

Ligament

The taut band.

Pivot and jewell (P&J)

A movement which rotates on a spindle, and pivots within an oil filled jewel. This type of movement

typically offers excellent vibration resistance characteristics.

Short-scale

Angle of deflection for a movement is usually 90 degrees but ANSI is 100 degrees in some products.

Long-scale

Angle of deflection for a movement is usually 240 degrees but is frequently referred to as 270 degree.

FSD

Full scale deflection.

ES

End scale.

Input

Electrical value from which the measurement is derived to achieve the full scale deflection of

the movement.

Linear

A term used to state that the input is constant, allowing for an even scaling.

Non linear

The opposite of linear, giving a scale shape which will cramp at some point on the dial. Usually

inaccurate below 20% of the full-scale value.

Logarithmic scaling

A log scale usually derived from a non linear DC output.

Scale

The graphical representation of the value being measured.

Dual arc

More than one set of figures on a dial plate.

Dial plate/scale plate

Surface on which the dial is drawn.

Calibration chart

A chart matching input values to scale mark, mainly used for complicated scales.

Enclosure rating

Usually expressed in the form of IP rating or as NEMA in America. This states the product,

resistance to the ingress of moisture and dust.

DIN

European standard meter shape. It is based on multiplies of 24mm, i.e. 48, 72, 96, 144 mm.

ANSI

American National Instrument Standard.

JIS

Japanese Instrument Standard.

BS89

Old British Standard usually refers to rectangular meter or “Fiesta” style products.

Switchboard meter

General term for long-scale instruments.

Panel meter

General name for short-scale instruments.

Analogue indicator

Generic term for instruments usually refers to a low accuracy meter. An indicator only.