Fluke 187 사용자 설명서

3-8

Keep the following in mind when measuring resistance:

•

 

Because the meter’s test current flows through all
possible paths between the probe tips, the measured
value of a resistor in a circuit is often different from
the resistor’s rated value.

•

 

The test leads can add 0.1 

Ω

 to 0.2 

Ω

 of error to

resistance measurements. To test the leads, touch
the probe tips together and read the resistance of the
leads. If necessary, you can press 

D

 to

automatically subtract this value.

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 30 M

Ω

 or

500 M

Ω

 ranges for in-circuit resistance measurements.

Continuity is the presence of a complete path for current
flow. The continuity test features a beeper that sounds if a
circuit is complete. The beeper allows you to perform
quick continuity tests without having to watch the display.

The continuity function detects intermittent opens and
shorts lasting as little as 1 millisecond (0.001 second).
These brief contacts cause the meter to emit a short beep.

To select continuity, turn the rotary switch to resistance
position, then press the blue button once. The continuity
symbol (

~

) appears in the display. Continuity uses

manual ranging only; autoranging is not available. Refer to
Figure 3-6 for continuity testing setup instructions.