To learn quantity of the electric power consumed by the site of a chain it is enough to measure electric power. It is possible to measure this parameter in two simple ways – or by means of the special device measuring power, or having performed measurements of size of current and tension.
It is required to you
- - multimeter or wattmeter;
- - screw-driver;
- - small hank of a wire;
- - knife.
Instruction
1. Cut off power an electrical circuit on which you will perform measurements: switch off the entrance automatic machine or the switch. Disconnect one of wires of a power supply from the input device of switching. On its place connect a necessary piece of a wire from the ends which are previously smoothed out by a knife at necessary length. Measure two pieces of a wire: length of a wire has to correspond to distance between a measuring hair parting and electric equipment.
2. Connect a wattmeter in an electrical circuit. In in advance prepared gap connect the channel of current. By means of wires connect the channel of tension to the output switch. Give tension to a chain. Determine the size of power consumption on the indicator of the device and record the received value as result of measurement by a direct method – P1.
3. Take measurements by an indirect method. In the prepared rupture of an electrical circuit connect a multimeter and transfer the device to the mode of measurement of current. Turn on the device of giving of tension - the entrance automatic machine or the switch. Record the data displayed on the device indicator. Disconnect chain tension. Disconnect a multimeter from a chain and restore the scheme of a chain such what it was before the taken measurements. Resume giving of tension in a chain. Change a multimeter operating mode to the voltage measurement mode. Make measurement of size of supply voltage on the weekend switch terminals by means of device probes. Record result of measurements. Increase value of current in amperes by value of tension in volts - power consumption in watts will be result.
4. Compare the values received as a result of measurements by a direct and indirect method. If the received sizes strongly differ from each other, for reliable result take measurements repeatedly.