The four wire kelvin method of measurement is preferred for resistance values below 100ω and all seaward milliohmmeters and microhmmeters use this method.
Low resistance measurement methods.
At this level it is important to use test equipment that will minimize errors introduced by the test lead resistance and or contact resistance between the probe and the material being tested.
Ohm meter method 2 measurement of medium resistance.
A low resistance measurement is typically a measurement below 1 000 ohm.
This can be done by comparing the unknown resistance with the standard resistance.
The methods are listed below.
Kelvin double bridge method.
2 wires carry the current known as the source or current leads and pass current through the rx.
Carey foster bridge method 3 measurement of high resistance.
These measurements are made using 4 separate wires.
Low resistance measurement method basically the trick is to pass a stable known amount of current through the low value resistor and measure the voltage drop across it.
These measurements are made using 4 separate wires.
Special connecting clips called kelvin clips are made to facilitate this kind of connection across a subject resistance.
Also at this level standing.
Some basic methods are suitable for low as well as medium resistances.
Following are the methods employed for measuring a resistance whose value is in the range 1ω 100kω ammeter voltmeter method.
This is the most crude and simplest method of measuring resistance.
Obviously the multimeter is connected permanently as shown in picture.
2 wires carry the current known as the source or current leads and pass current through the rx.
Kelvin method this method of measurement which avoids errors caused by wire resistance is called the kelvin or 4 wire method.
The four wire kelvin method of measurement is preferred for resistance values below 100 ω and all cropico milliohmmeters and microhmmeters use this method.
What is a low resistance measurement.
The dc potentiometer method of measurement of resistance is used for measuring the unknown resistance of low value.
1 measurement of low resistance.