NF FRA51602, Instruction Manual

Page: 154 / 286

4.6 Graph display mode
4
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24
FRA 51602
■ Converting measurement data to display parameters
The formulas for converting the various parameter formats that are used for measurement and display by
this instrument are explained in this section.
Let V
．
1
and V
．
2
respectively denote the voltage vectors obtained by Fourier transforms of the signals
measured at analysis input connectors CH1 and CH2. The parameters are defined as shown below.
V
1
[Vrms]
＝
|V
．
1
| V
2
[Vrms]
＝
|V
．
2
|
g
＝
|V
．
1
|÷|V
．
2
|
p [rad]
＝ ∠
V
．
1
−
∠
V
．
2
θ
1
[deg]
＝
p×180 ÷ π
Measurement frequency [Hz]
＝
f Measurement angular frequency [rad/s]
＝
ω
＝
2 × π × f
Table 4-3 Display parameter conversion formulas
○ Analysis mode: (CH1/CH2)
Display parameter Unit Formula Comments
R None g Gain
dBR dB 20×log
10
(g) Gain
θ
deg
θ
1
Phase
a
None g×cos(p) Real part of gain
b None g×sin(p) Imaginary part of gain
GD s
－
∂p/∂ω
Group delay
○ Analysis mode: (CH2/CH1)
Display parameter Unit Formula Comments
R None 1÷g Gain
dBR
dB
−20×log
10
(g) Gain
θ
deg
−θ
1
Phase
a None (1÷g)×cos(p) Real part of gain
b None
−(1÷g)×sin(p)
Imaginary part of gain
GD
s
∂p/∂ω
Group delay
○ Analysis mode: (CH1)
Display parameter Unit Formula Comments
R
Vrms V
1
CH1 amplitude
○ Analysis mode: (CH2)
Display parameter Unit Formula Comments
R Vrms V
2
CH2 amplitude