Gossen MetraWatt METRAHIT ENERGY TRMS System Multimeter Operating Instructions Manual page 32

Measurements: V/Hz/dB – PQ/
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).

Voltagelevel dB
Where U = U (reference level)
1 REF
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 the
unit of measure dB appears at the display.
Lowest measurable frequencies and maximum allowable volt-
ages are included 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
voltage component relative to the measuring range (600 mV 
600 V), and displayed.
32
– MHz/% – /nS/R
–
SL
U
1
U
2
 
20 log ----- -
=
U
1
/ – Temp – /m – W/Wh – A/Hz/thd
The default setting for the reference level is 0 dB = 0.775 V (1 mW
to 600 ). This value van be adjusted in the "SET" menu (see also
section 6.4):
U
2
MEASURE
1nFo 
...
SETUP
FUNC
dbrEF set: 00 .. 0 01 ... 99 V
ENTER
Note
No terminal resistors have been integrated into the device. It
performs measurement with a high input impedance of at
least 9 M (see 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!
FUNC
 SET system 
...
ENTER
FUNC

ENTER
GMC-I Messtechnik GmbH
 dbrEF