Resistance Measurement - Ferve F-1880 Manual Del Usuario

3.2 2 Resistance measurement

To avoid electrical shock and/or damage to the instrument, disconnect
circuit power and discharge all high-voltage capacitors before measuring
resistance.
The Meter's resistance ranges are 600.0 , 6.000k , 60.00k ,
600.0k , 6.000m and 60.00M .
To measure resistance (set up the Meter as shown in figure 3-2):
1. Set the rotary switch to * range.
2. Connect the black and red test leads to the COM and V terminals
respectively.
3. Connect the test leads to the circuit being measured and read the displayed
value.
Some tips for measuring resistance:
• The measured value of a resistor in a circuit is often different from the
resistor's rated value. This is because the Meter's test current flows
through all possible paths between the probe tips.
• In order to ensure the best accuracy in measurement of low resistance,
short the test leads before measurement and memory the test probe
resistance in mind. This necessary to subtract for the resistance of the
test leads.
• The resistance function can produce enough voltage to forward-bias
silicon diode or transistor junctions, causing them to conduct. To avoid
this, do not use the 60M range for in-circuit resistance measurements.
• On 60M range, the meter may take a few seconds to stabilize reading.
This is normal for high resistance measuring.
• When the input is not connected, i.e. at open circuit, the figure "OL" will
be displayed for the overrange condition.
Figure 3-2 Measuring Resistance
3.2.3 Diode Test Forward Bias
To avoid electrical shock and/or damage to the instrument, disconnect
circuit power and discharge all high-voltage capacitors before testing
diodes.
To test a diode out of a circuit (set up the Meter as shown in Figure 3-3):
1. Set the rotary switch to * range.
2. Press the SELECT key once to activate Diode Test.
3. Connect the black and red test leads to the COM and V terminals
respectively.
4. For forward-bias readings on any semiconductor component, place the red
test lead on the component's anode and place the black test lead on the
component's cathode.
5. The meter will show the approx. forward voltage of the diode.
In a circuit, a good diode (Si) should still produce a forward bias reading of 0.5V
to 0.8V; however, the reverse-bias reading can vary depending on the
resistance of other pathways between the probe tips.
Figure 3-3 Testing a Diode