Unitest Hexagon 710 - Voltage Attenuation Measure Db

5.2 Voltage Attenuation Measure dB
When selecting the AC voltage function, a measurement
value can be measured as ratio in dBm with reference to a
reference level.
The display dBm refers to a reference impedance at a pow-
er of 1 mW, whereby it is possible to set various reference
impedance values.
The dBm display is calculated using the following formula:
dBm = 20 x log
10 [Vx : VRef]
Example:
The reference voltage VRef = 0,7746V for a reference imped-
ance of 600Ω at 1mΩ. (U = P x R).
For a voltage measurement value of Vx = 9,8V the resulting
attenuation is:
20 x log
10 [9,8 V : 0,7746V] = 22,04 dB
Impedance values for selection:
4 Ω, 8 Ω, 16 Ω, 32 Ω, 50 Ω, 75 Ω, 93 Ω, 110 Ω, 125 Ω,
135 Ω, 150 Ω, 200 Ω, 250 Ω, 300 Ω, 500 Ω, 600 Ω, 800
Ω, 900 Ω, 1000 Ω, 1200 Ω
" Turn measurement function selection dial to V~.
" Connect the test leads to sockets and COM and
connect to UUT:
" The measurement value is displayed on the screen.
" Briefly press the SELECT key to change to the dB
measurement range.
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Voltage Measurement