Why Dry Sensor Design Is Key for Stability, Accuracy and In-Situ Validation

March 01, 2015      Scott, Product Line Director

Designing a stable sensor that will last over the lifetime of your thermal mass flow meter is the holy grail in thermal mass flow meter design.  The truth is that most flow meter manufacturers use a “wet” sensor design, filled with epoxies and cements.  As conditions in your application change, the sensor is heated and cooled over time, expanding and contracting the cement inside the sensor—and you know what happens to cement as it is repeatedly heated and then cooled, it shifts and cracks. This “wet” sensor design greatly compromises the accuracy of the thermal sensor over time.

Dry Sensor Technology

Due to these inherent challenges of “wet” sensor design, Sierra’s founder Dr. John G. Olin invented Dry Sensor technology which is manufactured in a proprietary and highly controlled process to form such close contact that little or no air gap exists inside the sensor and no organic filler cements are needed.

Since its invention in 1999, the patented DrySense™ sensor has been the cornerstone sensor technology used on all Sierra thermal mass flow meters. And dry, no-drift sensors have a big advantage during in-situ calibration validation. The all-metal, epoxy-free mechanical design provides the confidence that the in-situ calibration validation is actually valid.

Watch the video below to find out more about Sierra’s DrySense technology.

To learn more about how DrySense sensor technology in essential for accurate InSitu calibration, read the white paper.