Newtons4th PSM3750 NumetriQ, Startup Manual, Page: 70 / 104

PSM3750 Quick User Guide
Page 68
Selecting Test Conditions:
The Frequency and Voltage of the generator are selected on the PSM3750
Instrument. The actual Voltage across the DUT depends upon the Impedance of
the component at the test frequency and the impedance of the selected shunt.
The PSM3750 instrument clearly displays the measured Voltage across the DUT
and the measured Current through it.
To fix the test voltage at a specified level, enable ac trim on CH1 using the
“TRIM” menu on the PSM3750 and set the desired rms level for Vdut. The
instrument will then adjust the generator output level until the measured voltage
across the component is as specified.
NOTE:
AC level and tolerance parameters
are set for screenshot purposes only.
The optimum test conditions to use depend on the component or DUT and the
application as many components change their characteristics with frequency and
test voltage. The PSM3750 instrument can automatically select test conditions or
they can be entered manually.
DC offsets can also be added to the test voltage where required, for example
testing electrolytic capacitors which need a bias voltage. In this case, it may be
best to set the PSM3750 to AC coupling which will increase the measured
accuracy in cases where the AC signal is small relative to the DC level.