When selecting pressure sensor options, occasionally you will come across a choice of seal materials to choose depending on the sensor design.
An all welded construction provides a high integrity and homogeneous material design. The main disadvantages of this kind of sensor design is the lack of flexibility to customise for different applications, induced measurement errors from mechanical stresses caused by the welding process and higher manufacturing costs.
A sensor design that incorporates a standardised pressure sensing capsule which clips into place enables product designers to easily adapt it to a multitude of custom fittings. This helps to keep manufacturing lead time to a minimum and allows rapid development of new designs.
Featured pressure sensor products
DMK457 Marine Approved Pressure Transmitter - Marine approved pressure transmitter with 4-20mA current loop output for shipbuilding with optional CuNiFe housing for sea-water compatibility
700 bar, 10000 psi, 70 MPa Pressure Sensors, Transducers & Transmitters - High range pressure sensors with a measurement range from 0 to 700 bar, 10,000 psi, or 70 MPa.
One of the problem areas in sensor design is the effect on sensor performance following the rigid bonding of the process connector housing directly to the sensing element. Welding introduces heat into the construction which causes mechanical stress that relaxes over time causing incremental drift in measurement. Bonding with industrial adhesives also build in mechanical stress as the bond dries during manufacture and degrades over its service life with changes in temperature and pressure.
Using an elastomer material to seal between the sensing element and the pressure connector housing prevents the need to expose the assembly to stresses that result from a welded or glued joint. As there are no fixed seals in this design it is possible to quickly assemble without any intricate welding, cleaning and de-stressing processes. This type of sealing arrangement also opens up the choice of materials the design engineer is able to use without having to worry about the implications of welding or bonding together dissimilar materials.
There are many types of elastomer material such as Silicone, NBR/Buna-N, Viton / FKM, EPDM, Kalrez / FFKM and Chemraz. All have there own distinct properties making them the most suitable for certain operating temperatures and media types. This is why many sensors of this type of construction require the selection of a seal material to ensure media compatibility.
Featured pressure sensor products
IWPT Wireless Battery Powered Pressure Sensor and Receiver - Wireless battery powered pressure sensor and receiver system for connecting pressure sensors without wires to a central wireless receiver which converts each received pressure signal channel to a 1-5Vdc, 4-20mA output, USB, Ethernet TCP, RS232 RTU, RS485 RTU or 2G 3G 4G mobile cellular network.
Silicon Pressure Sensors - Silicon Pressure Sensors have silicon diaphragms which have a very high elasticity and semiconductor strain gauges which produce a high span sensitivity.
Related Help Guides
- Symptons and Causes of Damage to Pressure Transducer Diaphragms
- Process Connections
- How Gravity affects the performance of Pressure Transducers
- Why are Submersible applications so demanding of Pressure Transducers?
- Are all IP68 Water Resistant Protection Ratings the same
- Measuring the Pressure of Hot Media
Related Technical Terms
- Al2O3
- BFSG – Bonded Foil Strain Gauge
- Bonded Seal
- Bourdon Tube
- Burst Pressure
- Dry Cell
- Dry/Dry
- Food Grade
- g – Acceleration due to Gravity
- g Effect
- Hysteresis
- Isolation Diaphragm
- LVDT – Linear Variable Differential Transformer
- M10 x 1
- Mechanical Stop
- MTBF – Mean Time Between Failures
- Piezoresistive Strain Gauges
- Stainless Steel Pressure Sensors
- Static Line Pressure
- Wet/Dry
- Wet/Wet
- Wetted Parts
- Wheatstone Bridge Strain Gauge