Drawdown of artesian well

[dixie]

Hello all,
We have several artesian or "flow wells" at our site. There are Druck pressure transmitters in the wells at 35 feet. The problem we are having is programming our SLC505's to adjust for the natural variations of the static pressure which can range from 2psi in the winter to 12psi in the summer. 1psi = 2.31 ft. of water. You can see my delema. Does anyone have experience in this matter? Any help would be appreciated. Thanks in advance. Dixie

 

[buzzp]

What are you doing with the pressure reading? I guess I do not see any dilemma or more likely do not understand what you are doing with the reading.
If you want to know the water level, the pressure is a direct relationship. More info please.

 

[djs]

Hello;
What you need is a dynamic reference level to measure the difference or draw down value. One way to get this is to use a level reading from a well nearby that is not in use. Your SCADA system can then subtract this value from the operational wells and the result is the "drawdown".

 

[stevemcd]

I agree with DJS but if you do not have this facility then I assume you are looking for sudden pressure changes as the pumps stop working. The normal time changes will be slow (again an assumption) so if you store the pressure and then set a timer, when the timer runs out after say 1 minute check the current value against the stored value. If they are within a few percent then store the new value. If they are very different then flag up a warning or alarm