Sometimes there is a situation when it is necessary to measure the power cord resistance (search of possible break) or to check serviceability of the safety lock, an incandescence bulb, serviceability of TENa and so forth. By means of a multimeter these problems are solved easily and simply.
It is required to you
- multimeter, measuring wires with probes (go complete with a multimeter).
Instruction
1. Insert a measuring wire of black color into a multimeter COM nest, then insert a measuring wire of red color into VΩmA nest. Turning the switch of measurement ranges, turn on the device. For measurements of small resistance turn the switch to the sector Ω and put in position opposite to figure 200 (Measurement range of 0.1 - 200 Ohms). Close among themselves probes (check of a measuring chain on short circuit), on the display the digital value within 0.3 – 0.7 has to appear. This resistance of measuring wires. At each inclusion of a multimeter check the size of resistance of measuring wires. At its increase up to 0.8 Ohms replace measuring wires. At the opened wires the display has to show figure 1 in the extreme left register (very high resistance, infinity).
2. For measurement touch at the same time contacts of the checked chain. If the chain or the consumer of current are serviceable, indications of a multimeter will change: it will show a certain resistance. In a case with check on break of a power cord, the safety lock or "pro-calls" of wires, resistance has to be very low (within 0.7 – 1.5 Ohms). And when checking consumers of current (bulbs, TENy, network windings of transformers) about 150 – 200 Ohms can rise. And, such dependence is traced – the consumer of current, the less its resistance is more powerful.
3. If indications of a multimeter did not change, switch the range of measurement of resistance, having put the switch opposite to figure 2000 (0 – 2000 Ohms). If here indications of the display do not change, switch to the following range and again measure. Pay attention: at position of the handle of the switch opposite to figure 2000k the sensitivity of a multimeter is very high and if at the same time to undertake fingers of the left and right hand contacts of probes, the device will show body resistance that will distort indications of a multimeter.