Notes Regarding Pneumatic Instrumentation PDF Print E-mail

Pneumatic sensors listed in this catalog work on the force balance principle. Compressed air pressure is generated by the sensor to directly offset the hydrostatic pressure. This dynamic 1:1 balance between these two pressures (liquid and air) is functionally immune to temperature, hysteresis and long term drift.

Pneumatic components are fully compatible for use within continuous explosion hazard zones. An inert gas such as compressed nitrogen may be used when special considerations apply.

Compressed Air Supply (35 to 150 psig)
Recommended compressed air supply pressure required for system operation can be calculated as the maximum liquid pressure plus 20 psig. Calculate liquid pressure using formula listed below. Minimum supply pressure should not be less than 35 psig (241 kPa) nor greater than 150 psig (1034 kPa). All pneumatic instrumentation depends upon clean, dry and oil-free instrument grade air for optimal performance. Sub-micron, coalescing type filters should be installed upstream in the airline supplying the pneumatic components.


Actual air consumption is less than 0.16 scfm per unit.