The hottest suggestion on eliminating interference

Suggestions on eliminating interference of automatic resistance, capacitance and inductance tester

recently, when our salesperson visited some users, the users reported that there were some deviations in the measured values when testing small inductance and capacitance, and the measured values gradually increased with the passage of time. We found that some users ignored the interference to the instrument during the test on the operation site of their bridge, To ensure the requirements of test accuracy, because the pm6306 automatic tester has high sensitivity when testing small capacitance or inductance with high frequency, it should try to reduce the interference of static electricity, such as carrying an anti-static electric dry wrist guard; Or try to reduce the distributed impedance of the self-made fixture to improve the test accuracy of the instrument. These measures are very necessary. At the same time, we also recommend users to conduct zero calibration every 4 hours before and during the test of the instrument, so as to always maintain a high test accuracy of the instrument

now use pm9541a Kelvin four wire and greatly reduce the system control circuit test fixture as an example. The zero calibration steps of the instrument are as follows:

1) insert the Kelvin four wire test fixture, connect the power supply, and then turn on the machine, and the instrument enters the test state

2) under a fixed test condition (such as on some fixed stations in production, the test frequency, voltage and other conditions remain unchanged), the test condition can be set inside the machine first

3) press the zero trim key on the front panel of the instrument once

4) use the knob on the panel to select trim 1

5) press the zero trim key again

6) when the LCD screen displays the flashing "busy OCT", it turns into "busy SCT" after 2 seconds, that is, it prompts to short-circuit the test clamp

7) short-circuit two test clamps

8) press the zero trim key again, at this time, the instrument automatically zeros to the top of the test line of the test fixture

9) a few seconds later, the instrument shortcircuits and zeros successfully, and the screen displays "pass", On the contrary, it displays "fail"

10) press the zero trim key again, and the screen displays "pass", on the contrary, it displays "fail"

11) open the short-circuit test clamp

12) press the zero trim key again

13) after a few seconds, the instrument opens and zeros successfully, and the screen displays "pass", on the contrary, it displays "fail"

14) press the auto key, Enter the automatic test state

if the test conditions need to be constantly changed, you can choose the operation of full zero calibration, that is, the instrument will automatically calibrate all internal working point parameters. 4. The interface on the plug-in controller must be turned off and the controller power must be calibrated once. The zero calibration steps are as follows:

1) insert the test fixture, connect the power supply, and then start the machine, The instrument enters the test state

2) under a fixed test condition (such as on a fixed production station, the test frequency, voltage and other conditions remain unchanged), you can first set the test condition inside the machine

3) press the zero trim key on the front panel of the instrument

4) select trim a

5) press the zero trim key again

6) the LCD screen displays flashing "busy OCT"

7) open the test fixture

8) press the zero trim key again

9) the instrument will have a 15 second countdown to automatic open circuit zeroing, and then the screen displays a flashing "busy SCT"

10) short circuit the test fixture

11) press the zero trim key again

12) the instrument will have a 15 second countdown to automatic short circuit zeroing

13) zeroing is successful, and the screen displays "pass", On the contrary, the display fails "fal"

14) press the auto key once to enter the automatic test state

precautions:

1) when changing the test conditions, it is necessary to set the new test conditions inside the instrument and perform a zero calibration operation again

2) when the temperature of the test environment is 10 ℃ different from the temperature at zero calibration, please conduct zero calibration again

3) the user-made test fixture should be connected with the instrument through the test line to make a zero calibration of secondary short circuit and open circuit that makes the aluminum exhibition more and more influential

if the self-made test fixture makes a short circuit and the open circuit zero calibration cannot pass, it indicates that the self-made fixture has affected the zero point of the instrument and cannot guarantee the test accuracy of the instrument