Ceramic sensors are made of ceramic materials. Ceramic materials have natural resistance to abrasion. This quality helps protect sensors against corrosion.
In a typical pressure sensor with stainless steel diaphragm, pressure is measured by the movement of a diaphragm, and the movement is measured by a measurement cell behind the diaphragm. A transfer medium like oil transfers the pressure on to the diaphragm. There is the risk of contamination of this filling oil. The metal diaphragm is also thin and fragile to facilitate easy transfer of oil, hence leading to a lot of wear and tear.
Using a pressure sensor with ceramic diaphragm eliminates the need of a transfer medium and a metal diaphragm. In a ceramic sensor, pressure to be measured is directly applied onto the sensing diaphragm. Non usage of filling oil gives the name dry cells to ceramic sensors.
Apart from the difference in construction between ceramic pressure sensors and steel diaphragm sensors, ceramic pressure sensors have more advantages:
Advantages of Ceramic Pressure Sensors:
- The sensing diaphragms of ceramic sensor are 10 times harder than stainless steel diaphragms
- Ceramic sensors are resistant to abrasion, corrosion and have superior chemical resistance
- They cost lower and have a long service life
- Ceramic sensors are dry cells, hence they do not impact the ambient environment with oil leaks
- Ceramic pressure sensors withstand extreme temperatures and extreme pressure differences. Applications that call for measuring high pressure of 116000 psi (800 bar) to measuring low pressures of 0.9 psi (0.06 bar), use ceramic pressure sensors. They are sensitive enough to low pressure while being highly resistant to over-pressures. These can withstand temperatures as high as 135°C or as low as -40°C.
- They also withstand high levels of shock and vibration
- Performance is consistent, even after multiple operating cycles
- There is very less hydrogen permeation in ceramic sensors compared to steel diaphragm sensors
- The versatile nature of ceramic sensors make them highly compatible with any kind of medium
- Ceramic sensors have high overload resistance, which means they can handle elevated levels of over-pressure without any permanent damage
- Minute pressure changes are measured much more effectively and accurately by ceramic sensors compared to steel diaphragm sensors
