The Art of Practical and Precise Strain Based ... - Webprofile.info

More documents

Recommendations

Info

Strain-Based Measurement Introduction:fluid-filled bellows arrangement on one or both sides of the bendingdiaphragm as shown in Figure 1-48. In biomedical uses, the low-costdiffused semiconductor sensors are isolated from the medium by usingsilicone-gel materials that provide medium isolation by occupying thevolume that the moisture-laden media would otherwise occupy. Thisisolation method is sometimes referred to as isolation by the exclusionmethod and is depicted in Figure 1-49.FIGURE 1-48. Medium-Isolated, Filled Sensor Designs:LowPressureHighPressurePressure-SensingDiaphragm ModuleHeader AssemblyFill Fluid(Usually Silicon Oil)LeadwiresMedium-Isolating Diaphragms(Very Flexible)CHAPTER 1-82 The Art of Practical and Precise Strain Based Measurement 2nd Edition © 1999
Applications Note 1-13:FIGURE 1-49. Medium Isolation By ÒExclusionÓ:Silicone Gel FillSensorFlush Diaphragms:The second common type of strain-gaged diaphragm pressure sensor (Figure1-50) is the flush-diaphragm design where the sensing diaphragm isflush with the end of the sensor, eliminating all dead-volume cavities. Theadvantage of this style of sensor is that the elimination of the Helmholtzcavity over the sensor diaphragm allows much-improved frequencyresponses to be realized. The minimum mass of the flush-diaphragm sensorresults in high insensitivity to vibration and shock inputs. Since the sensitivemember is exposed, with no mechanical protection, care in handlingmust be exercised. The asymmetry of the structural diaphragm clamp andminimized excess structural material results in a sensor design that willshow different sensitivities for pressure-induced bending in the two bendingdirections. In the case of the differential sensor, it is highly recommendedthat the device be calibrated in both pressure directions assensitivity mismatches of as much as 3% are common in asymmetricallysupportedsensor structures such as the flush-diaphragm designs as shownin Figure 1-51.The Art of Practical and Precise Strain Based Measurement 2nd Edition © 1999 CHAPTER 1-83
Page 1 and 2:
The Art of Practical andPrecise Str
Page 3 and 4:
Special Credits:Mrs. Helen Pierson,
Page 5 and 6:
Table of ContentsBy James G. Pierso
Page 8 and 9:
ContentsApplications Note 4-10:Lead
Page 10:
ContentsCHAPTER 8Electrical Conside
Page 13 and 14:
CHAPTER 1Strain-BasedMeasurementInt
Page 15 and 16:
Applications Note 1-1: Introduction
Page 17 and 18:
Applications Note 1-1: Introduction
Page 19 and 20:
Applications Note 1-2:The Art of Ap
Page 21 and 22:
Applications Note 1-31. The presenc
Page 23 and 24:
Applications Note 1-3result in a pe
Page 25 and 26:
Applications Note 1-4:The measureme
Page 27 and 28:
Applications Note 1-4:uncertainty i
Page 29 and 30:
Applications Note 1-5:All strain-ba
Page 31 and 32:
Applications Note 1-6:Applications
Page 33 and 34:
Applications Note 1-6:ical size of
Page 35 and 36:
Applications Note 1-6:and where:j i
Page 37 and 38:
Applications Note 1-6:5. millivolts
Page 39:
Applications Note 1-6:.Electrodynam
Page 44 and 45: Strain-Based Measurement Introducti
Page 104: Strain-Based Measurement Introducti
show all

The Art of Practical and Precise Strain Based ... - Webprofile.info

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?