Omicron CMC 356, Руководство пользователя

Страница: 78 / 142

CMC 356 Reference Manual
78
Figure 6-26:
Typical phase error as
function of the input
frequency
Conditions: integration time 1 s, measurement signal sinusoidal, sampling
rate = 28.44 kHz, measurement range 100 V, excitation on both channels
20 Vrms.
The maximum input frequency for the phase measurement depends on the
sampling rate.
Table 6-36:
Sampling rate and input
frequency range
Note:
1. The measurement accuracy of phase can be improved by:
• increasing the integration time
• enabling the recursive averaging function
2. When measuring very small phase shifts (less than 0.2 °), the sign
(positive or negative) of the measurement results can not be definitely
determined. If this causes a problem, please refer to the phase
measurement in the harmonic analysis.
3. For measuring phase, the input voltage should be greater than 5 % of full
scale. An overload of the measurement channel does not negatively
affect the obtainable accuracy.
Phase Error as a Function of Frequency
(SR = 28.44 kHz, R: 100 V, Uin = 20 Vrm s)
0
0.05
0.1
0.15
0.2
0.25
0.3
0 100 200 300 400 500 600 700 800 900 1000
Frequency / Hz
Ph
as
e
Er
ro
r /
°
Phase error as function of input frequency
(fs = 28.44 kHz, range = 100 V, Uin = 20 Vrms)
Phase.
err
or
in
°
Frequency in Hz
Sampling rate Input frequency range
28.44 kHz 10 Hz ... 2.30 kHz
9.48 kHz 10 Hz ... 750 Hz
3.16 kHz 10 Hz ... 250 Hz