Standard signal in fields Current and Pneumatic

[amshah]

Based on my erlier reply and begas link, i would like to summurise here, if not correct- please correct

1) pneumatic : 3-15 psi- signal starts other then zero is for live and dead zero, 3 to 15 psi is meant for linear response of the flapper nozzle design in this region.

2) 4-20ma : above zero requires for live and dead zero, in europe still it is 0 to 20 ma.

4 to 20 is requires to convert the same to 1 to 5 volt which normally can be measured at receiver side very easily with standard highily (.0005%) accurate 250 ohm resistor. If it is 4 to 21 or other values, non standard resistor is requied to manufacture which is difficult to get from open market and there (may be) a std. for resister values.
and above 25 mA shock hazards remains to human cell.

Hope it meets your requirement.

Nice point for discussion : to refresh basics