User Manual
GMC-I Messtechnik GmbH 33
V/Hz/dB – , Temperature, and A/Hz Measurements
Alternating Voltage Level Measurement (dB)
Voltage level measurement is used in order to
ascertain overall attenuation or boosting of a
transmission system (shown here as a 4-pole
setup)
.
Where U
1
= U
REF
(reference level) = 0.775 V
Result > 1: boosting
Result < 1: attenuation
Ð Manually select the measuring range for the voltage amplitude.
When the instrument is switched to dB measurement, the pre-
viously selected voltage measuring range remains active.
Ð Repeatedly press the multifunction key FUNC | ENTER until unit
of measure dB appears at the display.
Lowest measurable frequencies and maximum allowable volt-
ages are listed in section 8, “Technical Data”,.
The level measurement function is now activated. The measured
value is calculated based upon the RMS value of the alternating volt-
age component relative to the measuring range (300 mV to 600 V),
and displayed.
The default value for the reference level is 0 dB = 0.775 V (1 mW
to 600 ). This value is a fixed setting and is displayed at the left-
hand auxiliary display (R:00.775 v).
Note
No terminal resistors have been integrated into the device. It
performs measurement with a high input impedance of
5M.
Input impedance for voltage measurement is listed under
technical data.
In order to be able to perform correct measurement at non-
terminated devices under test, the terminating resistor must
be connected to the terminals. Be sure to take power loss at
the terminating resistor into consideration!
U
1
U
2
VoltageLevel dB20
U
2
U
1
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