Normal operating position of the panel meter is vertical. The position is marked on the scale and the meters are correspondingly calibrated.
Moving coil instruments are suitable for a wide range of DC application, particularly for remote indication when use with a suitable transducer (0..1mA or 4..20mAdc). Scales are linear and can be drawn to suit customer specification together with any chosen title.
Overload ratings :
DC Ammeters : 1.2 x rated current continuously 10 x rated current for 5s
DC Voltmeters : 1.2 x rated voltage continuously 2 x rated voltage for 5s
Accuracy :
DC Ammeters : Class index 1.5 (Class index 1.0 available )
DC Voltmeters : Class index 1.5 (Class index 1.0 available)
Information required with order :
Type reference and model
Details of required scale and any optional features. Details of required electrical rating or input transformer
ratio Example : Moving coil, NDA96-24 Input 4..20mA, Scale 0..200A
Moving coil instruments are suitable for a wide range of AC Rectified instruments are available for AC
applications and have a long burden. Scales are linear and can be drawn to suit customer specification together with any chosen title.
Frequency :
AC rectifier instruments are calibrated on a sinusoidal wave form at 50Hz. but are suitable for use without significant error on any frequency from 20Hz. To 10kHz. (2.5kHz. when internal CT is used).
Overload ratings :
AC Ammeters : 1.2 x rated current continuously 10 x rated current for 5s
AC Voltmeters :1.2 x rated voltage continuously 2 x rated voltage for 5s
Accuracy :
AC Ammeters : Class index 1.5 (Class index 1.0 available )
AC Voltmeters : Class index 1.5 (Class index 1.0 available)
Information required with order :
Type reference and model
Details of required scale and any optional features. Details of required electrical rating or input transformer ratio Example : Moving coil, NAA96-24 Input 4..20mA, Scale 0..200A
A power factor indicator with quadrant and long scale is available in size 96mm. these instruments are designed for measuring power factor in three phase three wire network with balanced load or in single phase network.
The moving coil movement is driven by an internal transducer circuit. Scale are central at unity and are available up to ±180 electrical degrees. For remote indication, moving coil instruments can be supplied to operate with transducer (0..1mA or 4..20mAdc). All instruments are 96 x 96mm.
Position indicators can be used for many remote monitoring applications. For example, the position of transformer taps, mechanical values or sluice gates can be determined accurately.
Scale marking are kept to a minimum to present a clear pleasing appearance ensuring that the instruments can be read with ease from distance of several feet. An internally mounted static circuit ensure that normal supply variations do not affect the stated accuracy. For remote indication, these instruments can be supplied to operate with transducer (0..1mA or 4..20mA). Instruments are available in 96x96mm. and 144x144mm. cases.
Voltage influence :
A static circuit is included which ensures that the effect of ±10% supply voltage variation does not affect the stated accuracy of indication. When the sensing resistor is positioned in some distance away from the indicator, the line impedance can affect the accuracy of indication.
For example, an impedance of 10Ω per line causes an indication error not greater than 0.25% at 2.4kΩ sensing potentiometer.
Information required with order :
Type reference and model. Details of required electrical rating and number of taps and resistance per tap scale required