Is 450 Feet to Far for Accurate Pressure Sensor Readings?


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I have a micro 1100. Need to run both pressure sensors 450 ft. I have 18 gauge/4 shielded Pairs. I did a test with the 1000 ft roll. 7 Ohms total. Voltage (24 Vdc) Dropped only 200 mil amps. Not Bad. Note: I need only 450 ft +/- and NOT THE 1000 FT. The SIGNAL WAS OFF A LITTLE.

Had it set for 0 to 100. Tank Level. I had 10 to 99.
Lots of numbers in your post, but some critical ones (and engineering units) are missing.

I doubt you "dropped only 200 mil(li) amps".

More likely your transmitter is a voltage transmitter and it lost 200mV over the wiring.

Current loops (milliamps) are 4-20mA and the nature of a current loop is that it doesn't lose any current (with the exception of a ground loop); the current has to be the same in all parts of the loop circuit.

450 foot runs are what current loops are made for and there's probably 200,000 head pressure level sensors world wide that work just fine as 4-20mA current loops with no loss on the electrical side.

But if you have voltage output transducers and are need to use them, you'll have to live with whatever signal voltage drop you get over that distance. The error will be proportional across the span, so you could correct for the error at the receiver.
Yes. At 1000 feet of 18 gage shielded copper wire pairs hooked up (the roll) I had 10 to 99 Reading With it working to read 0 to 100. Norm. I was thinking that at 450 feet it may work or I will be able to work with adjustments in the PLC or with some resistors to get it close enough to work.