Sapphire SI-9002 User Manual

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Sapphire Instruments Co., Ltd.

Calibration Procedure of SI-9002

1. How to open the case, please follow the steps.

1.1 Remove the battery lid.

1.2 You will see the two screws and loosen them.

Fig. 1

1.3 Near the BNC cable side, there are two protuberant mortises. Use fingers to push back and pull

upward.

Fig. 2

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1.4 Use fingers to press the bottom case inward, and pull it backward and upward.

Fig.3

1.5 Hold the bottom case and push back (to input lines

direction).

Fig.4

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1.6 You will see the two metal cases. There is one screw on the PCB. Loosen it, then the whole metal case

can be taken out. There are two wires still connected with the upper case. Leaves them

there.

Fig. 5

1.7 The metal case is illustrated as follows:

Fig. 6

2. Explanation of adjustment point. Please refer to Fig. 7.

(1) SW1: Switch for selecting attenuation ratio.

(2) SW2: Power switch.

(3) VR4: Variable resistor for adjusting offset when SW1 at attenuation 1/200.

(4) VR2: Variable resistor for adjusting offset when SW1 at attenuation 1/20.

(5) VR1: Variable resistor for adjusting low frequency CMRR.

(6) VR3: Variable resistor for adjusting accuracy.

(7) VC1: Variable capacitor for adjusting square wave compensation and high frequency CMRR.

(8) VC2: Variable capacitor for adjusting square wave compensation.

(9) CON1: Power jack for connecting to 6VDC power adapter.