Search results
Results from the WOW.Com Content Network
Ayrton shunt switching principle. The Ayrton shunt or universal shunt is a high-resistance shunt used in galvanometers to increase their range [1] without changing the damping. [2] The circuit is named after its inventor William E. Ayrton. [3] Multirange ammeters that use this technique are more accurate than those using a make-before-break ...
For direct measurement, the ammeter is connected in series with the circuit in which the current is to be measured. An ammeter usually has low resistance so that it does not cause a significant voltage drop in the circuit being measured. Instruments used to measure smaller currents, in the milliampere or microampere range, are designated as ...
That the voltage drop across the shunt is proportional to its current flow, i.e. ohm's law, makes the low resistance current shunt a very popular choice for current measurement system with its low cost and high reliability. Both alternating currents (AC) and direct currents (DC) can be measured with the shunt resistor.
An ammeter shunt allows the measurement of current values too large to be directly measured by a particular ammeter. In this case, a separate shunt, a resistor of very low but accurately known resistance, is placed in parallel with a voltmeter, so that virtually all of the current to be measured will flow through the shunt (provided that the ...
An ammeter shunt is a special type of current-sensing resistor, having four terminals and a value in milliohms or even micro-ohms. Current-measuring instruments, by themselves, can usually accept only limited currents. To measure high currents, the current passes through the shunt across which the voltage drop is measured and interpreted as ...
The pascal (Pa) or kilopascal (kPa) as a unit of pressure measurement is widely used throughout the world and has largely replaced the pounds per square inch (psi) unit, except in some countries that still use the imperial measurement system or the US customary system, including the United States.
Other units of pressure include: The bar (symbol: bar), defined as 100 kPa exactly. The atmosphere (symbol: atm), defined as 101.325 kPa exactly. These four pressure units are used in different settings. For example, the bar is used in meteorology to report atmospheric pressures. [7] The torr is used in high-vacuum physics and engineering. [8] [9]
Measurement of electrical quantities may be done to measure electrical parameters of a system. Using transducers , physical properties such as temperature, pressure, flow, force, and many others can be converted into electrical signals, which can then be conveniently measured and recorded.