- 1). Connect the measurement probes to the meter. Two leads are provided with the meter. Plug the red lead into the positive terminal and the black lead into the negative terminal.
- 2). Switch on the Sperry SP-5A meter by rotating the dial on the front. Select the 250V voltage function. Place the measurement probes across the two input terminals of the motor. The needle on the meter display should rotate to the right. Read the value of the voltage off the middle scale which ranges from 0V to 250V.
- 3). Rotate the dial on the front of the meter to the 250 milliamp (mA) current measurement setting. Place the measurement probes across the two inputs of the motor. The needle on the meter display will rotate to the right. Read the measured value of current off the middle scale that ranges from 0 mA to 250 mA.
- 4). Multiply the measured value of current (in amps) by the measured value of voltage (in volts) in order to get the power in watts. For example if 150 volts is measured for the voltage and 100 mAmps (0.1A) is the measured for the current, then the power is: P=VI= 150 x 0.1 = 15 watts