Simple Voltage and Current Measurement :: essays research papers

Experiment I fair Voltage and Current standardmentObjectiveThe objective of this experiment was to measuring rod the Voltage and Current. Upon completion of this experiment I was able to1)Set the DC power supply to a specific potential.2)Properly connect the voltmeter to measure voltage.3)Measure flow rate with the ammeter.4)Measure resistance with the ohmmeter.5)Determine the accuracy of a given meter indication.TheoryThe theory required for this experiment was an understanding of Ohms Law. Ohms Law is the algebraic relationship between voltage and current for a resistor. Resistance is the capacity of materials to impede the flow of current or electric charge. Ohms Law expresses the voltage as a function of the current. It was also necessary that the concept of measurement accuracy be understood. This is discussed below.Accuracy is of primary importance in an experimental work. The tolerance quoted by the meter manufacturer allows us to calculate the accuracy of any readingtake n with that particular meter. For example, assume that the dc voltage scale on aparticular multimeter is rated at 3% of full scale. This means that a reading onthe 10V scale is accurate to ( 0.03%)(10) = 0.3V. Thus, a reading of 9V on the10V scale indicates a true voltage, which lies between 8.7 and 9.3 V. A reading of 1Von the scale would indicate a true voltage between 0.7 and 1.3 V. At this point, the error is 30% Any reading less than 10% of full scale should be viewed with suspicion since most meters are very inaccurate n this range. roach DiagramsFor this experiment we used a Power supply source, voltmeter/ammeter/ohmmeter.Fig 1.1 Power Supply and voltmeter in parallelPower SupplyVoltmeter-Fig 1.2 Simple voltage measurement circuit.aab a ba ad c c dc dFig 1.3 Simple current measurement circuitPower Supply(Be sure current Icontrol is atmaximum setting)Fig 1.4 Circuit to measure resistanceProcedureTo measure the voltage output of the power supply, we connected the voltmeter as shown in Fig. 1.1. We made sure that the voltmeter is always connected in parallel with the voltage being measured. Before turning on the power, we set the voltmeter voltage range to a DC value higher than the highest voltage we anticipate to measure. This precaution must be observed with all meters in order to avoid the possibility of burning out an expensive instrument.We then set the current control to maximum current and adjust the output voltage of the supply to values of 2.5, 10, and 15.