There are three types of the devices allowing to measure resistance: digital, arrow and bridge. Methods of use of these measuring instruments differ. The skilled house master has to be able to measure resistance, using any of them.
It is required to you
- digital multimeter, arrow tester, ohmmeter or bridge measuring instrument of resistance.
Instruction
1. Regardless of which from devices you are going to use, the resistor which resistance will be measured follows vypayat from the scheme. Previously it should be disconnected from the power supply and to discharge in it condensers.
2. To measure resistance by a digital multimeter, choose as the switch the mode of measurement of resistance and the most rough mode. Include wires in the device nests corresponding to the mode of measurement of resistance then connect the resistor to probes. If resistance not of the resistor, and an element which conductivityhas depends from the direction of current is measured, consider that the digital multimeter at the red probe has positive tension. Consecutive switching of the switch towards more exact limits achieve disappearance of an overload. Read indications of the indicator, and by position of the switch find out in what units they are expressed.
3. Measurement of resistance an arrow tester is performed also, but taking into account a number of its features, namely: - at an arrow tester the positive pole in most cases is in the mode of measurement of resistance on the black probe; - zero scale of resistance are in its end; - after each switching of a limit the probes of the device should be closed, exposed to the shooter the special regulator on zero, and only after that to carry out measurement; - at some arrow testers the choice of a limit is carried out not by turn of the handle, but shift of the plug; - also some arrow devices demand to include, besides the choice of a limit, the mode of measurement of resistance the separate switch.
4. Use the bridge measuring instrument so. Having connected to it the resistor, rearrange the switch of limits in one of extreme provisions. Rotate the regulator from one end of a scale in another. If at the same time the indicator of balance of the bridge (light, sound or arrow) never worked, choose other limit. On it scroll the regulator from one end in another again. This operation is repeated until the bridge does not manage to be balanced. Now on the regulator determine resistance by a scale, and by position of the switch of limits - in what units it is expressed.