Applications 4
When Measuring Resistance
When Measuring Resistance
Two-Wire Configuration
The meter measures resistance in a
The
Correcting for Test Lead Resistance
The resistance of the test leads can introduce error when measuring low resistances. Typi- cal test leads may add as much as 0.5 Ω to readings.
To correct for this error using the relative modifier (REL):
1.Insert test leads in the Xand COM input terminals.
2.Turn the meter on and press Oto select the resistance function.
3.Select the manual range mode by pressing E, T, or U. Then press Uor Tto select the desired range. This is necessary because autoranging is turned off (and the meter is locked in the range it is in) when the relative mode is selected.
4.Touch the test leads together. The display will show the resistance of the test leads.
5.With the test leads still touching, press K. The resistance in the test leads becomes the relative base and the meter should show 0 Ω .
6.As long as the relative modifier remains selected, the resistance readings shown on the display will be the resistance measured minus the relative base, which in this case is the resistance in the test leads.
Table
Medium and Fast Reading Rates
Range | Typical Full Scale Voltage |
|
|
Range
Slow Reading Rate
Typical Full Scale Voltage
300Ω
3kΩ
30kΩ
300kΩ
3MΩ
30MΩ
300MΩ
0.25
0.24
0.29
0.29
0.3
2.25
2.9
100Ω
1000 Ω
10kΩ
300kΩ
1000 kΩ
10MΩ
100MΩ
0.09
0.10
0.11
0.11
0.12
0.65
2.75
Open circuit voltage is 3.2 V (maximum) on the 100 Ω , 300 Ω , 30 MΩ , 100 MΩ , and 300 MΩ ranges, and 1.5 V (maximum) on all other ranges.
True RMS Measurements
The meter measures the true rms value of ac voltages and currents. In physical terms, the rms
