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Preventing Pressure Transducers from Drifting

Background

Traditionally pressure transducers drift over time and during installation. This has been a continual problem that has requires the end user to offset the reading either at the pressure transducer or the data acquisition system.

The traditional fix has been zero and span potentiometers. However, the offset of the zero has eliminated the original factory calibration by offsetting the curve. This results in inaccurate readings. (See Figure 1)

 

Why Do They Drift?

Transducers have drifted due to several reasons which include physical damage to the diaphragm and curing of the bonding adhesive between the diaphragm and the strain gauge over periods of time.

Solution

Curing of Adhesive

Eliminate the adhesive completely by using sputtered film deposition.  (See Figure 2)

Physical Damage

The sputtering technique causes the signal per deflection to increase dramatically, meaning the diaphragm flexes less for an equivalent pressure. Therefore we are able to use a thicker diaphragm, which will cause no physical damage.

 Transducer size comparison. The image shows a comparison of a typical 20k PSI transducer against an equivalent Gems 3100

Transducer size comparison. The image shows a
comparison of a typical 20k PSI transducer against an
equivalent Gems 3100

Gem’s Product

  • The Gems Model 3100 Pressure Transducer is the most rugged transducer for high shock applications.
  • The all welded design has no oil fill and offers unsurpassed reliability.
  • 0 to 32,000 PSI

  • Accuracy 0.25% FS

  • Long term drift 0.2% FS for the life of the sensor.

  • Compact design (See Figure 3)