Posted: September 13th, 2017

Introduction procedure, results, discussion and conclusion

Lab report: Introduction procedure, results, discussion and conclusion

A sample guideline for writing a lab report
Introduction:
Give a brief explanation of the subject addressed in the lab. You will be graded on your contribution, NOT cleaver resource choices.

Procedure:
DC Voltage Measurement Procedure
The DC voltage measurement positions are: 200mV, 2000mV, 20V, 200V, and 300V.
To measure DC voltage, connect the meter as follows:
1. Set the rotary switch to an appropriate measurement position in the DC voltage range. The
rotary switch should be placed in the desired position prior to connecting the leads. This position
should not be changed while the leads are connected.
2. Connect the test leads in parallel across with the component being measured. The measured
value shows on the display.
3. When the DC voltage measurement has been completed, disconnect the testing leads from the
circuit under test.
Notes:
DO NOT connect the DMM in series while using the DC Voltage Function.
If the value of DC voltage to be measured is unknown, use the maximum measurement position
(300V) and reduce the range step by step until a satisfactory reading is obtained.
In each DC voltage range, the DMM has an input impedance of greater then 1 MΩ. This loading
effect can cause measurement errors in high impedance circuits. If the circuit impedance is less
than 1 KΩ, the error is negligible (0.1% or less).
Source: MCM DMM Model 72-7940 Operating Manual
DC Current Measurement Procedure
The DC current measurement positions are: 2000 μA, 20 mA, and 200 mA.
To measure DC current, connect the meter as follows:
1. Turn off power to the circuits. Discharge all high-voltage capacitors.
2. Set the rotary switch to an appropriate measurement position in the DC current range. The
rotary switch should be placed in the desired position prior to connecting leads. This position
should not be changed while the leads are connected.
3. Break the circuit continuity of the current path to be tested. Connect the red lead in series to
the more positive side of the current path break and the black lead to the more negative side of
the current path break.
4. Turn on the DC power to the circuit. The measured value shows on the display.
Notes:
DO NOT connect the DMM in parallel across the load while using the DC Current Function.
If the value of DC current to be measured is unknown, use the maximum measurement position
(200 mA) and reduce the range step by step until a satisfactory reading is obtained.
After completing the DC current measurement, turn off the DC power and disconnect the
connection between the testing leads and the circuit under test.
Source: MCM DMM Model 72-7940 Operating Manual

Results:

Nominal Value(OHM) DMM Measurement(OHM)
R1 220 218.5
R2 2200 2188
R3 6800 66700

REQ 9220 9106.5
Calculated Series Current(12 VDC)=1.317*10^-3Ame
Calculated Value(V) DMM Measurement
VR1 2622 0.04
VR2 26256 0.38
VR3 800400 11.53

Vreq 3078 11.95
Measured Serise Current(12 VDC)=1.312*10-3Ame

Discussion:
By using the multi meter the maximum allowable DC current is 2000MA/20mA/ 200mA
1.
By using the multi meter the maximum allowable AC current is not available.
2.
Nominal Value(OHM) DMM Measurement(OHM)
R1 220 218.5
R2 2200 2188
R3 6800 66700

REQ 9220 9106.5
Calculated Series Current(12 VDC)=1.317*10^-3Ame
Calculated Value(V) DMM Measurement
VR1 2622 0.04
VR2 26256 0.38
VR3 800400 11.53

Vreq 3078 11.95
Measured Serise Current(12 VDC)=1.312*10-3Ame

3. A.
If a DMM is connected in series with a DC voltage source and another function other than the DC current function is selected: the DMM will be having an infinite number of resistance.
B.
If a DMM is connected in parallel across a load with a DC voltage source applied and the DC current function is selected: the DMM voltage source will be having an unrelatedly value.