7
General Notes for using the IM-SG
continued
The rotary knob -
Rotate slowly to sweep through the
frequency range.
The display
- The display shows the generator frequency "
f”
and the measured impedance "Z" simultaneously.
Harness Compensation
If making critical measurements, like those needed when
trying to derive Thiele/Small parameters for a speaker driver
(Page X), the IM-SG can compensate for harness
impedance to obtain the highest accuracy possible.
1. Turn on the IM-SG by holding the
On
button for 1
second.
2. Adjust frequency to approximately 500 Hz.
3. Connect the test harness to the IM-SG and short the
red and black test leads together by clipping them
together.
4. Wait for Impedance reading to settle, it should settle to
less than 0.50 ohms, if not you may have a defective
harness. The reading must settle to below 0.50 ohms
to continue.
5. Press and hold the
Range
button for 3 seconds.
6. The IM-SG will display "CALIBRATED", the impedance
should now read 0.00 ohms or -0.00 ohms. A lower
case "c" is displayed next to the
symbol to indicate
that the reading is now compensated for test harness
impedance!
7. Compensation is canceled by powering the IM-SG off
and then back on.
Summary of Contents for SMD IM-SG
Page 1: ...IM SG Impedance Meter Signal Generator Owner s Manual ...
Page 20: ...20 Figure 2 Impedance curve of a typical 4 ohm 1 tweeter Notice the fS at 1 59 kHz ...
Page 22: ...22 Figure 3 fC of a single 4 ohm 15 inch subwoofer in a 2 cubic feet sealed box ...
Page 44: ...44 Notes ...
Page 45: ...45 Notes ...
