Level Sensor

Hello to all
I've noticed a strange beavioural on our sterilizing process (sterilizer with Mitsubishi FX2N-16MR and a floated level sensor)
When we start produce; milk has to be sent in a tank in which there's the sensor (float is on the low level): on this state a valve has to be open to let milk coming in tank
But although the low level is detected (I/0: ON) by the plc we must hold the float in this position during a certain time before the valve open finally
After this; the process continue normally, ie: when low level sensor is detected the valve open automatically (we don't need to hold the float anymore)

ANY HELP WOULD BE GRATLY APPRECIATED

what are your current method ur ladder...if you could be more
what u have done ..maybe i could help

It sounds like there is a de-bounce timer on the float switch, meaning it must be on for a time to allow the valve to open. This prevents the valve opening and closing as the milk sloshes around!

markie said:

It sounds like there is a de-bounce timer on the float switch, meaning it must be on for a time to allow the valve to open. This prevents the valve opening and closing as the milk sloshes around!

Click to expand...

Hi I agree with this. Interesting though the OP says only debounces the first time, and subsequent fill requests dont debounce... at least that is how i interpret it

Cheers

I think the reason why the float only works with a timer the first time, is for the milk not to mix with water when the milk first pushes the water out.

yes that makes sense... let the vessel drain at start up then fill normally

Cheers

This is what we do, to save the "Low Low" (LL) level probe.

level sensor

Thank to all for your interesting posts that all make sense
mostly Nonuke's one
Last week we had trouble with the sensor (internal wiring) and we moved a bit the position of the low level cellule in order to solve the "problem" (the sensor is constitued with two glassed cellues fitted in an inox tube) but the result is the same
this give me the idea to download the programm in order to verify the "timer at startup" as one of you said
Thank you to all