MFC flow display is unstable, how to find and solve it?

Many factors contribute to unstable flow display; it needs to be confirmed whether it's an issue with the display meter or MFC 's problem.

1. Check the display meter

The display meter is tested separately. Connect the back-end 15 pin connector settings with flow detection via short circuit, then turn the setting knob clockwise to observe the instantaneous flow display on the front panel, checking if it can range from 0 to full scale. If it cannot be adjusted normally from 0 to full scale, we can conclude that the display meter is faulty. For troubleshooting different display meter models, please refer to " D08 Series Display Meter Quick Troubleshooting Guide ” Introduction.

2. Check M FC

If the display meter issue can be ruled out, it is likely that the actual flow control is unstable or M FC problem. Typically, troubleshooting can be performed by checking the following aspects one by one to quickly identify the cause of the fault ， and thus fundamentally solve the problem. ：

■ May be ground wire interference; check the grounding system. 。

■ May be spatial interference, mainly electromagnetic interference; appropriate shielding, staying away from interference sources, and using shielded cables are possible methods.

■ The gas source pressure may be too low, too high, or unstable; the gas source pressure needs to be adjusted, check if there is any leakage in the gas path, and stabilize the gas source pressure.

■ The internal resistance of the gas source may be too large; it needs to be reduced (for large flows, ensure valves are fully open, pipes are thicker, or use multiple gas cylinders to ensure sufficient gas supply and improve gas source supply capacity).

■ May be contamination, such as dust impurities in the gas source, or easy liquefaction; filters, dryers, or appropriate heating should be installed before the channel. If special gases like silane are used, pay attention to the sealing of pipelines and the dryness of the gas source.

■ May be M FC circuit or control valve fault, requiring return to factory for repair.