# Determine Calibration Range of Pneumatic Pressure Transmitter

The following storage vessel holds water. A pneumatic pressure transmitter located at the bottom infers water level by hydrostatic pressure (head).

## Pneumatic Pressure Transmitter

Determine the calibration range of this pressure transmitter in order to properly translate the range of vessel level (0 to 18 feet) into an output signal of 3 to 15 PSI.

Please express the transmitter’s calibration range in units of inches W.C. (inches of water column).

Then, determine the following (assuming the transmitter has been properly calibrated for the application):

Transmitter output signal (PSI) at 12 feet of level.

Water level at 5.9 PSI signal output.

Lower range-values (LRV): 0 inches W.C. input = 3 PSI output

Upper range-values (URV): 216 inches W.C. input = 15 PSI output

Transmitter output signal (PSI) at 12 feet of level = 11 PSI

Water level at 5.9 PSI signal output = 4.35 feet

Note: Pneumatic pressure transmitters are outdated and these are replaced with electronic smart transmitters. These are discussed for educational purpose only.