The
PR-285 is designed to measure very low differential
pressure generated by annubar, venturi, and other liquid
flow measurement devices. The transducer can measure
differential pressure down to 0 to 20 inches water
column and, at the same time, can withstand up to 300
PSIG of system static pressure.
Within
the transducer, static pressure is transmitted through
isolator diaphragms
and silicone fill fluid to a sensing diaphragm.
The sensing diaphragm, located within the electronics housing,
is a stretched spring element that deflects when
differential
pressure is applied to it. The spring's displacement
is proportional to the differential pressure.
Two capacitor plates, located at either ends of the spring,
convert
the differential capacitance detected between
the spring and plates into a 4 to 20 mA signal.
