NF FRA5014, Instruction Manual

Page: 94 / 107

7.7 Performance Test
FRA5014 7-6
7.7.5 IMRR test
Connection: OUTPUT OSCILLATOR
→
INPUT CH2, CH3, CH4, CH1 central conductor and external conductor (for CH1 test)
→
INPUT CH1, CH3, CH4, CH2 central conductor and external conductor (for CH2 test)
→
INPUT CH1, CH2, CH4, CH3 central conductor and external conductor (for CH3 test)
→
INPUT CH1, CH2, CH3, CH4 central conductor and external conductor (for CH4 test)
Use a T divider, etc., to split the oscillator’s output into two output channels.
In the channel under test, short the input connector’s central conductor and external
conductor, then apply a signal between the input connector and the case. Input a
drive signal to the other channels.
Setting: After initializing settings, set the frequency as 60 Hz, the integration time as 10 s,
the AC amplitude as 7.07 Vrms, and turn output on to have the settings reflected in
the output.
Measurement: Perform a spot measurement and read the results.
Judgment: For CH1 test, normal when gain > 120 dB, for CH2, CH3, and CH4 test, normal
when gain <
−
120 dB.
In an IMRR or dynamic range test, the signal being measured is extremely weak, so
several measurements may be required to obtain stable results, but this is normal .
CH1 IMRR test example
CH1 CH2 OSCILLATOR
FRA
Signal ground
Coaxial cable
Input shorted
CH3 CH4