Which signal to choose?0-10v or 4-20ma?

[mordred]

I see you've already looked at the Baluff linear transducer I've found they are reliable and fairly stable although if your working high washdown you may want to look at applying silicon to the connection as the pins often get corroded enough to break in the transducer pin ports

 

[rdrast]

Turck? Temposonics?

Both have 4-20ma Ouput devices.

 

[ghettofreeryder]

4-20mA is superior for long distances, like those encountered in a steel mill, oil refinery or chemical plant that covers, literally, square miles - where
- signals have to go long distances with assurance of a live zero (4mA, rather than 0mA),
- good resistance to noise
- wiring needs to be only 2 wires per circuit, where the power to the transmitter is supplied over the signal wires.
- smart functions like re-ranging with HART is important for inventory and processs reasons.

They use process transmitters like this:

Those criteria are not as critical (if at all) when instrumenting a molding machine, where 6 or 7 steps covers the length of the machine and 2 or 3 steps cover the width of the machine. You don't drive a pick-up truck to get out to the transmitter. Running 3 wires, rather than 2 wires, over a 'long' run of 10m is no big deal.

Note that most 'smart' process grade pressure transmitters that are 4-20mA devices produce an output change 3x to 10x per second, depending on brand & model. Is this response adequate for the injection pressure?

In comparison, industrial pressure transmitters, frequently 3 wire 0-10V models are either analog or low end digital uP models with 1mS-10mS response, limited scaling (tweaking a zero or a span pot), but they work great as a dedicated device. Many models come in either voltage outputs or current outputs.

Industrials tend to look like this:

As long as you know your pressure range up front, one of the industrials would serve you well.

Dan

The reason for differences in what the transmitters all depends on where the transmitter is being used. The first transmitter looks like its mounted in an explosion proof enclosure. Need this to be installed in a classified area. THe latter of the two is general purpose. For the most part, the performance wont differ that much. Saying that, 4-20 mA transmitters are what the whole oil and gas industry uses. I cant vouch for other industries though.

 

[Steve@HSDCorp]

MTS makes a G-Series or R-Series. I have two 9-inch analog probes in stock, brand new. I can set them up with 4-20mA for you to use. If you are interseted please get a hold of me. I can work with pricing on this for you as well.

Steve

[email protected] 208-773-4731

 

[Mickey]

Steve, this thread is 3 years old. Hopefully the OP has his problem solved by now.

 

[Steve@HSDCorp]

Thanks, new to this. Just found the date once you said something. Have a good one.

 

[TConnolly]

Mickey, it appears that Steve is dredging up old threads in an effort to develop sales leads.