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
TPSA Precision High Pressure Transducer - High pressure transducer for pressure testing applications with pressure ranges from 0...4 bar (60 psi) up to 0...1000 bar (15,000 psi) gauge with a measurement accuracy of 0.1%. 
DCT 531 Modbus RTU RS485 Pressure Sensor - The DCT 531 digital pressure sensor has a Modbus RTU RS485 interface for transmitting pressure readings over a digital sensor network.
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
DMK 331 Ceramic Diaphragm Industrial Pressure Transmitter - This pressure transmitter can be supplied with a PVDF process connector so that it can be used to measure the pressure of acids and other corrosive chemicals.
High Speed Pressure Sensors - xplore high-speed pressure sensors designed for capturing rapid transients and dynamic events. Understand frequency response, rise time, and system limitations for accurate test and research data.
Related Help Guides
- Symptons and Causes of Damage to Pressure Transducer Diaphragms
- Process Connections
- Measuring the Pressure of Hot Media
- 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
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
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