transducer wiring to digital read out

Thread Starter

bomrat

Joined Dec 13, 2009
25
hi, i have a transducer , it is 24v in, 1-6vdc out.
i wire the transducer to the power and check output with a multimeter and i get the .98v on the output leg, if i put the digital readout on gnd and the output leg it won't display. do i need a resistor inline? and if so what value, 10k?
thanks
 

shteii01

Joined Feb 19, 2010
4,644
The one time I worked with pressure transducer, the part info mentioned 5 kOhm or greater load, but I did not really pay attention because I had it hooked up to op-amp which by its nature has really high input resistance so I assumed that transducer was seeing a really large resistor load.

Bottom line. Check transducer info for what it needs or contact manufacturer.
 

strantor

Joined Oct 3, 2010
6,798
like this

you need to put 5 bar pressure on it to get it to work.
Where do you see that info? The datasheet for the PA21SR shows that it comes in several ranges from 1 to 600 bar. Overpressure limit for the 1 bar model is 3 bar. Hopefully OP will check his model/rating before applying 5 bar.

It sounds like you're bench testing (no pressure applied to transducer) so .98V is correct and should be expected from a transducer with specified 1-6V range.

Your drawing shows a two-wire "LCD readout 0-30VDC" meter from MPJA.com. I could not find a two wire digital meter on MPJA.com with those specs, and I seriously doubt that such a thing exists. A digital meter must have sufficient voltage to power itself before it can measure anything. It is more likely that you have one of the only (2) two-wire digital 30V meter models offered by MPJA; the larger 4.5-30VDC meters, in red, blue, and green, or the smaller 3.5-30VDC model in red, blue, and green.

You need to be using a 3 wire meter like this.
 
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