TABLE OF CONTENTS There is an extremely large number of pressure transducers available in today's test instrumentation marketplace. These pressure transducers use several different operating principles and are designed to operate in a wide variety of test conditions. The types of pressure transducers include strain gauge, piezoelectric, piezoresistive, capacitive, variable reluctance, resistive, and integrated circuit. Table 4-2 provides a summary of the advantages and disadvantages of the various types of pressure transducers.
| Sensor Type | Advantages | Disadvantages |
|---|---|---|
| Thermocouples | inexpensive rugged fast response standardized output wide measurement range no self-heating | moderate accuracy subject to drift or instability nonlinear low signal output cold junction reference required |
| RTDs | good accuracy good stability standardized output good linearity low self-heating | slow response sensitive to shock and vibration large sensing element lead-wire sensitive |
| Thermistors | fast response high sensitivity small size lead-wire insensitive | nonstandard output highly nonlinear poor stability high self-heating |
| Integrated circuit sensors | inexpensive linear output small size high sensitivity | narrow temperature range moderate accuracy slow response |
| Infrared sensors | no target contact wide temperature range fast response good stability | emissivity sensitive large size high cost environment sensitive |
| Sensor Type | Advantages | Disadvantages |
|---|---|---|
| Strain Gauge | Capable of DC response | Large size Limited temperature range Low sensitivity |
| Piezoelectric | Small size Wide temperature range Fast response Self-generating signal Rugged | AC response only Vibration sensitive Low sensitivity High output impedance Temperature sensitive |
| Piezo-resistive | Small size DC response High sensitivity Fast response | Temperature sensitive |
| Capacitive | Low hysteresis Good linearity Good stability |
