generator and detector are required. When inductance is being measured in ac or dc, it should be realized
that iron-core inductors are sensitive to current variations. Quantitative measurements of dc effects can be
made by supplying current to the unknown inductor through the EXT BIAS terminal. Use the following
steps to make inductance measurements:
1. Turn the DET GAIN control to 1.
2. Set the FUNCTION switch to L PARALLEL if Q is greater than 10 to L SERIES if Q is less than
3. Set L-R-C decade dials to 3.000 and D-Q dial to maximum.
4. Connect the unknown inductor to the R-L terminals 1 and 2
5. Set the GEN DET switch to INT 1 kHz.
6. Adjust the RANGE switch for minimum detector deflection.
7. Adjust the L-R-C decade dials and D-Q dial alternately for a minimum meter deflection, turning
the DET GAIN control clockwise to increase sensitivity as necessary.
8. The measured inductance is the product of the L-R-C decade dial setting times the RANGE
9. The measured storage factor (Q) is read directly from the D-Q dial, inner scale for parallel and
outer scale for series inductance.
The important points of this chapter are summarized in the following paragraphs. You should be
familiar with these points before continuing with your studies of test equipment.
A MULTIMETER is a single meter that combines the functions of a dc ammeter, a dc voltmeter, an
ac ammeter, an ac voltmeter, and an ohmmeter. Observe the following safety precautions when using a
De-energize and discharge the circuit completely before connecting a multimeter.
Never apply power to the circuit while you are measuring resistance with an ohmmeter.
Connect the ammeter in series for current measurements and in parallel for voltage
Be certain the multimeter is switched to ac before attempting to measure ac circuits.
Observe proper dc polarity when measuring dc circuits.
Always start with the highest voltage or current range.
Select a final range that allows a reading near the middle of the scale.
Adjust the "0 ohms" reading after changing resistance ranges and before making a resistance