You have to have 4mA flowing thru the input resistors and adjust the zero to give a 0V on the output of the amplifiers.

You have to have 20mA flowing thru the input resistors and adjust the span to give a +5V on the output of the amplifiers.

EDIT: added a drawing with the settings in Red for 20mA and Blue for 4mA.

Attached Thumbnails

 

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Eric " Good enough is Perfect "
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hai i am ravi,
i want to know the value of span resistor is it 100k or 100 ohms please reply for current to voltage converter circuit

 

The Span is 5K, the sense resistor is a 100R [Zero]

Is this what you mean.?

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Eric " Good enough is Perfect "
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The gain of the circuit is set entirely by the 100Ω pot. The 5K pot sets the offset voltage. The voltage gain of the two amplifiers is fixed at 1 each for a total voltage gain of 1. In my view the 100Ω pot should be called GAIN (or SPAN) and the 5K pot should be called OFFSET (or ZERO).

I think the proper way to adjust the circuit is to apply 4 mA and adjust the "zero" and/or "span" pots as necessary to achieve a convenient 0V reference output. Then apply 20 mA and adjust the "zero" pot for a 5V output. That sets the proper gain. Last, apply 4 mA again and set the "span" pot for a 0V output. That sets the proper offset.

 

if 4-20ma to 0-5V,need G.Adj,value is 50K.
If 0-10V to 0-5V,need G.adj, value is 50K
if 0-10V to 4-20ma,need G.adj,value is 50K,and need ZA,value is 2K