NF FRA5022, Инструкция по эксплуатации

Страница: 129 / 145

7.7 Performance Testing
FRA5022
7-6
7.7.5 IMRR Test
Connection: OUTPUT OSCILLATOR
→
INPUT CH2 and CH1 core conductor and outer conductor together
(when testing CH1)
→
INPUT CH1 and CH2 core conductor and outer conductor together
(when testing CH2)
Separate the oscillator output in two by using a T shape divider.
Short circuit the input connector core conductor and external conductor of
the channel under test and send a signal between the case and the input
connector. Input a drive signal to the other channels.
Settings: After initialization the settings, Frequency: 60Hz, Integration time: 10s
AC amplitude 7.07Vrms, press the ON AC/DC key to reflect the changes in
output.
Measurement: Press the SPOT key and execute a spot measurement of CH2/CH1.
Evaluation: Correct if tested CH1 gain
＞
120dB, tested CH2 gain
＜ -
120dB.
To measure a very small signal in IMRR or dynamic range tests, it is
necessary to repeat the measurement a few times until the value stabilizes.
This behavior is correct.
7.7.6 Dynamic Range Test
Connection: OUTPUT OSCILLATOR
→
INPUT CH2 CH1 input is short circuited
(when testing CH1)
OUTPUT OSCILLATOR
→
INPUT CH1 CH2 input is short circuited
(when testing CH2)
Settings: After initialization the settings,
Minimum frequency: 10Hz, Maximum frequency: 100kHz, Frequency points:
40, integration time 10s, AC amplitude 7.07Vrms, press the ON AC/DC key to
reflect the changes in output.
Measurement: Press the DOWN or UP key and execute a sweep measurement of
CH2/CH1. When there is a lot of electromagnetic interferences a set
frequency may not fit the specified range. Keep the noise source at a
distance and conduct the tests.
Evaluation: Correct if tested CH1 gain
＞
120dB, tested CH2 gain
＜ -
120dB.
CH1 CH2 OSCILLATOR
FRA
Signal ground
Coaxial cable
Example of CH1 IMRR test
Input short circuit
CH1 CH2 OSCILLATOR
FRA
Coaxial cable
Example of CH1 dynamic range test
Input short circuit