PRICE LIST LINKS OF AE AMPERE METER,RISHAB AMPERE METER,YOKINS AMPERE METER
AE Ampere Meter Price List w.e.f 1st August 2013 (VIEW)
RISHAB Ampere Meter Price List w.e.f 1st August 2013 (VIEW)
YOKINS Ampere MeterPrice List w.e.f February 2015 (VIEW)
Introduction of Ampere Meter
An ammeter is a measuring instrument used to measure the electric current in a circuit. Electric currents are measured in amperes (A), hence the name. Instruments used to measure smaller currents, in the milliampere or microampere range, are designated as milliammeters or microammeters. Early ammeters were laboratory instruments which relied on the Earth's magnetic field for operation.
Types of Ampere Meter
The D'Arsonval galvanometer is a ammeter. It uses magnetic deflection, where current passing through a coil causes the coil to move in a magnetic field. The voltage drop across the coil is kept to a minimum to minimize resistance across the ammeter in any circuit into which it is inserted. The modern form of this instrument was developed by Edward Weston, and uses two spiral springs to provide the restoring force. By maintaining a uniform air gap between the iron core of the instrument and the poles of its permanent magnet, the instrument has good linearity and accuracy. Basic meter movements can have full-scale deflection for currents from about 25 microamperes to 10 milli amperes and have linear scales.
Moving iron ammeters use a piece of iron which moves when acted upon by the electromagnetic force of a fixed coil of wire. This type of meter responds to both direct and alternating currents (as opposed to the moving coil ammeter, which works on direct current only). The iron element consists of a moving vane attached to a pointer, and a fixed vane, surrounded by a coil. As alternating or direct current flows through the coil and induces a magnetic field in both vanes, the vanes repel each other and the moving vane deflects against the restoring force provided by fine helical springs. The non-linear scale of these meters makes them unpopular.
Operating Principle of Ampere Meter
Analog ammeters and electric meters are classed together as there are no fundamental differences in their operating principles. The action of all ammeters and electric meters, with the exception of electrostatic type of instruments, depends upon a deflecting torque produced by an electric current .in an ammeter this torque is produced by a current to be measured or by a fraction of it. In a electric meter this torque is produced by a current which is proportional to the voltage to be measured. Thus all analog electric meters and ammeters are essentially current measuring devices.
The essential requirement of measuring instruments are
(i) that its introduction into the circuit, where measurements are to be made, does not alter the circuit conditions
(ii)the power consumed by them for their operation is small.
Ammeters are connected in the series with the circuit whose current is to be measured. The power loss in an ammeter is (I^2.Ra) where I is the current to be measured Ra is the resistance of the ammeter therefore ammeter should have low electrical resistance so that they cause a small voltage drop and consequently absorb small power.
AE AMPERE METER,RISHAB AMPERE METER,YOKINS AMPERE METER