Fluke 187 user manual Using Conductance for High Resistance Tests

Making Measurements	3
Using Conductance for High Resistance Tests

Continuity testing provides you with both a visual indication of the state encountered (usually near 0 resistance for a short or OL for an open) and an audible beep when the input is low.

In continuity, a short means a measured value less than 5% of full scale. You can raise this threshold by manually selecting a higher range.

You can select whether the beeper comes on for open or short conditions, as follows:

•Press [ to enable the beeper for opens.

•Press ] to enable the beeper for shorts.

The Hz ( N) and FAST MN MX ( O M) functions are not available when continuity is selected. All other pushbutton functions are available. The blue key cycles among resistance, continuity, and conductance.

Using Conductance for High Resistance Tests

Conductance, the inverse of resistance, is the ability of a circuit to pass current. High values of conductance correspond to low values of resistance.

The unit of conductance is the Siemens (S). The meter’s 50 nS range measures conductance in nanosiemens (1 nS = 0.000000001 Siemens). Because such small amounts of conductance correspond to extremely high resistance, the nS range lets you determine the resistance of components up to 100,000 MΩ , or 100,000,000,000 Ω (1 nS = 1,000 MΩ ).

To measure conductance, set up the meter as shown in Figure 3-7; then press the blue key until the nS indicator appears on the display.

With conductance measurements, the following pushbutton operations cannot be used:

•Frequency ( N)

•FAST MN MX ( O M)

•Manual ranging ( R)

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