you need
  • digital multimeter, switch tester, ohmmeter or bridge resistance meter.
No matter which of the devices you are going to use a resistor, resistance which will be measured, should be vypayat from the scheme.Previously it should be disconnected from the power supply and discharge the capacitors in it.
To measure the resistance digital multimeter, measurement mode select switch resistance and the most brutal regime.Wires include the socket device, the corresponding resistance measurement mode, then connect the schupam resistor.If the measured resistance no resistor, and the element in which the conductivity depends on the direction of the current, note that the DMM on the red probe is present positive napryazhenie.Posledovatelnym changeover switch
in the direction of more precise limits Achieve the overload disappears.Read the indicator, and on the position of the switch find out what units they are expressed.
resistance measurement pointer tester made the same, but with the number of features, namely: - the switch from tester to measure the resistance mode, the positive pole in most cases is a black dipstick;
- zero scale resistance is at its end;
- after every switching limit test leads should be close, put the arrow special regulator to zero, and only then carry out the measurement;
- some testers a choice limit switches is carried out not by turning the knob, and the rearrangement of the plug;
- some turnouts devices require, in addition to select the limit resistance measurement mode include separate switch.
Mostovoi meter are wrong.Resistor connected to it, rearrange the limit switch to one of the end positions.Turn the knob from one end of the scale to the other.If this indicator is the balance of the bridge (light, sound or dial) never worked, choose another limit.It again scroll knob from one end to the other.This operation is repeated until the bridge is balanced fail.Now, on a scale to determine the controller resistance , and on the Status of limit switches - in what units it is expressed.