"The Probe" 7ML 12011EF00

Hi Tired,

I fear that the issue here is being caused by the gate control. We only provide a 4-20 mA output from the Probe LU which, I guess, is being fed into some sort of controller to raise or lower the gate. The input on this controller should be "dampened" either internally, or with the use of some sort of PID control, we have no ability to dampen the signal from the Probe LU or provide switched control. We see this sort of thing with weigh feeders when one of the PID variables is not correctly set.

The solution suggested by Dan might help in delaying the inevitable seeking by slowing down the change in level passed across to the gate controller if there is no PID control (see PID controller - Wikipedia). Some oscillation is to be expected while the controller optimizes the gate height, but if you are simply going to and from the same higher and lower height values of the gate then it could be that the integral control (the I in PID) is set too high/low (high if the oscillations are fast, low if the oscilations are slow).

How is the gate being controlled? Is there a PID controller between the Probe LU and the gate or in the gate itself? Is there a process control system? If there is not a controller, I think it wise to implement some sort of control. If there is a control system, you should be able to create a PID control within its programming.

Hope that this helps - apologies for not replying sooner,

Regards,

Richard