forum for industrial automation

is there a forum on the net where people can discuss the sensors , transmitters , control elements etc. , shortly industrial automation elements ?

why not start one here?

thanks
hazey

Hitit, you have landed right on the site that can do this.
Start a discussion, ask what you like. The people on here are vastly experienced in all automation fields.

We are not just programmers that write logic according to the signals we recieve from outside.

We wire, fit and spec the sensors that give us these signals - ask away.

ok friends .. here is my problem ...
we have 5 broken transmitters. these transmitters were mounted to open tanks directly with flanges in order to measure the level. the factory hasnt been used during the winter.. and the people who were responsible to dismount these transmitters have been late for this, and dismount them 1 month after the shutdown.. but during this 1 month , the remaining water and liquids in the tanks have frozen.. and this ice has forced the membranes of the transmitters , and made the silicone oil leaked. so the heads of the transmitters are deformed. is there a way or a solution to refill it with silicone oil . if we send them to the supplier , they will return them to abroad , and this will take maybe a few months . is there a quick solution?

sorry for my english, and thanks for your interest

Hi, What make are they?
When you say level transmitters I presume you mean an analog output?
Regards Alan Case

yes , transmitters produce 4-20 mA according to the pressure applied onto their diaphragm . if the height of tank is 3 metres , and the liquid is water then a range of 0-300 mBar is ok. Pressure=height*densty

You should be able to do a field fix. Usually this type of transmitter has an external diaphragm and silicon fluid fill to protect the actual pressure sensor from fouling and corrosion. The actual sensor picks up the pressure from the fluid fill as it is displaced by the diaphragm. You should be able to get repair diaphragms and fluid from the manufacturer and rebuild them. They may give you some guff about loss of accuracy, etc. but if you releive them of the responsibility they should sell you the parts.

Hi Hitit,

You are measuring the height of the water in your on the hydrostatic principle. So, what kind of pressure transmitter are you using? In other words what's the size of the membranes? I Bought a few years ago 50 pressure transmitters of Fisher Rosemount and I had the same problem with some of them. The answer of Fisher was 'It's better (read cheaper) to buy new ones instead of replacing the membrane'.
I personaly think they were right for several reasons
1. What is the accurancy going to be after the replacement of the
membrane ?
2. How long is it going to take to reveive the spareparts and to
repair them?
3. What's the cost of a new one?

Conclussion I bought new ones

Kind regards Rudi Frederix

Just an Idea, but wouldn't ultrasonic level detection be better for this kind of application? Then it can freeze all it wants, with no maintenance at all.