Design features of pressure sensors
Wheatstone bridge
Aluminum bonding
pads
Monocrystal
sapphire diaphragm
Titanium diaphragm
- Sensitive element of pressure sensors is a double-layer sapphire-titanium diaphragm with monocrystal silicon resistance strain gauges.
- Exceptional insulating properties and radiation resistance of sapphire enable to use the sensitive element within temperature range from -200 to +350°С under the effect of high electromagnetic interferences and radiation.
- Monocrystal sapphire diaphragm is a perfect elastic element that due to connection with titanium acquires the best quality as to the deformation level, and preserves its elastic properties up to 400°С.
- Monocrystal silicon resistance strain gauges are automatically connected with sapphire (heteroepitaxy method) and provide almost no hysteresis or fatigue effects.
- Strain gauges elements are manufactured in groups by solid-state microelectronic methods and provide high quality and good repeatability of the output parameters.
Strain gauge pressure sensors are divided into three types:
1.Double-diaphragm pressure sensors (from 0-0.6 to 0-1 MPa)
Double-diahragm pressure sensor consists of strain gauge diaphragm and intermediate titanium diaphragm which are rigidly connected by a stem.
The intermediate diaphragm is effected by the measured medium pressure. The intermediate diaphragm converses the measured medium pressure into the force. The force is transmitted on the solid center of the strain-sensitive membrane by the stem.
The lowest operating pressure of double-diaphragm sensors is 0-0,06 MPa. The diameter of intermediate diaphragm is 28 mm.
- strain-sensitive diaphragm
- dielectrical collector
- titanium body
- stem
- intermediate titanium diaphragm
2.Single diaphragm welded pressure sensors (from 0-1,6 to 0-10 MPa)
Single diaphragm welded pressure sensor consists of strain-sensitive diaphragm welded to the body.
The internal cavity of strain-sensitive diaphragm is effected by the measured medium pressure. The lowest operating pressure is 0-1,6 MPa. The diameter of strain-sensitive diaphragm is 5,5 mm.
- strain-sensitive diaphragm
- dielectrical collector
- titanium body
3.One-piece pressure sensors with single diaphragm (from 0-16 to 0-500 MPa)
This sensor is designed without welding connections and is very stable at the influence of impulse or high pressures.
The diameter of strain-sensitive diaphragm is from 2,5 to 4,0 mm.
- strain-sensitive diaphragm
- dielectrical collector
- titanium body