I want to procure IS passive barriers for analog inputs like pressure, temp and flow transmitters. Flow transmitters are basically vortex type transmitters with local display cum tantalizer in a separate enclosure.
Now the question is:

Whether for these flow transmitters a different type/model of barrier will be required? I expect that the total loop resistance will be high with this type of flow transmitter rather then the conventional pressure or temp transmitter.

I have heard of some repeater barriers but I am not sure how to use them and whether these will be suited for this application. Is it required to check the IS calculations for the integrity of the system and where can I get some sample calculations?

Regards
NG

 

Better go with MTL 40** series. I used it.

 

There are some good technical papers in the MTL website http://www.mtl-inst.com/

The 4xxx range mounts on a backplane. The 5xxx range mount directly on DIN rail. We have used both systems quite extensively.

You need to prepare a document for each barrier/isolator and haz area inst. combination

First thing you need to check is that the barrier cannont supply more current, voltage or power than the field instrument is certified for. Look at I max, V max, P max values on ATEX certificates for both devices.

Next you have to look at the Capacitiance and Inductance figures. Subtract the field instrument values from the barrier/isolator values and this tells you the Capacitance and Inductance values that are permitted in the hazardous area cabling. Work out the max cable length permitted and check this is greater than the cable lengths installed. I have a template for this calculation if required.

 

Could you please send the template for the calculation to shinesonline [at] gmail.com.

Thanks
Shine

 

Try also Pepperl + Fuchs..

www.pepperl-fuchs.com