Yes kai has done a very great job !

Thanks, Sanjeev.

Erik , do you say that an RCV420 is an overkill for industrial uses . And it is enough to use simple differential amplifiers ? .I have got a project in which we have to measure AC coach (Railway) temperature and humidity what will you suggest a costly RCV420 or simple opamp in differential mode as Kai has suggested .But there is a lot of difference in CMRR almost 50% !

I don't want to answer for Erik, but if I'm allowed, I would like to show my point-of-view.

For ME, the main difference between RCV420 and discrete solution like Erik, me and others formerly suggested, is CMRR. It's worth to find out, whether super high CMRR is needed at all! Please have a look at application notes of datasheet of RCV420. There you can see, that in many situations RCV420 is used in combination with XTR101, or similar, where you finally reference current return of transducer to ground (0V) of RCV420. In these cases high CMRR is NOT needed, because common mode noise is nearly eliminated by this connection. Then, a rather simple circuit will do the job.

If, on the other hand, ground of transducer is floating relative to ground of '4-20mA to 0-5V' converter, rather high common mode noise is to be expected, and a real high CMRR may be needed. So, it highly depends on how your transducer is powered and grounded. Tell us about, and we'll find a solution, hopefully...

Kai