Operation

The pressure sensing element is a differential

capacitance cell for pressure measurements ranging

from 0.1 in to 5 in (3.04 mm to 127 mm) of water (25

kPa to 1.0 kPa), or piezoresistive (silicon) sensors for

pressure measurements ranging from 5 in (127 mm) of

water to 10 in (1.0 kPa to 2.5 kPa).

The capacitance cell is capable of sensing very low,

negative or differential pressures.

A very lightweight, responsive diaphragm within the

cell deflects a small amount when a small pressure

is applied. This deflection results in a change in

capacitance which is then detected and amplified

electronically.

The piezoresistive sensor is a solid state device

designed in a Wheatstone bridge configuration. When

pressure is applied to the device, the resistance of the

bridge changes by a small amount. The output of the

bridge is ratiometric to the supply voltage, and a small

change in resistance is detected as a change in output

voltage.

Standard Pressure Ranges

US Units

Pressure Code

Pressure Range

Maximum Safe

Momentary

Overpressure

03E

0to0.300inH20

-

04E

0to0.500inH20

-

05E

0to1.00inH20

-

06E

0 to 2.00 in H20

20 inH2O

07E

0to3.00inH20

-

08E

0to5.00inH20

-

Metric Units, Millimeters of Water

Pressure Code

Pressure Range

Maximum Safe

Momentary

Overpressure

03M

0to7.50mmH20

-

04M

0to10.00mmH20

-

05M

0to25.0mmH20

-

06M

0 to 50.0 mm H20

500 mm

07M

0to75.0mmH20

-

08M

0to100mmH20

-

Metric Units, Pascal

Pressure Code

Pressure Range

Maximum Safe

Momentary

Overpressure

03P

0to75.0Pa

-

04P

0to100.0Pa

-

05P

0to250Pa

-

06P

0 to 500 Pa

5 kPa

07P

0to750Pa

-

08P

0to1.00kPa

-