What is a pressure transmitter?
A pressure transmitter is a mechanical device that measures the expansive force of a liquid or gaseous sample.
Also known as a pressure transducer, this type of sensor is typically composed of a pressure sensitive surface area made of steel, silicon, or other materials depending upon the analyte’s composition. Behind these surfaces are electronic components capable of converting the applied force of the sample upon the pressure sensor into an electrical signal.
Pressure is generally measured as a quantity of force per unit of surface area, and is expressed as the value required to stop a liquid, gas, or vapor from expanding. Various derived units are used to quantify pressure, including:
As a proportion of / relation to a pascal (Pa), or a single newton per square meter (1 N/m2);
A value of pounds per square inch (psi).
Pressure sensitive environments such as the gas, petrochemical, laboratory, and pharmaceutical industries often require pressure transmitters to monitor the applied force of liquids and gasses as a value of either Pa or psi. This necessitates the precise integration of pressure transmitters into rapid electrical conversion equipment, to ensure results are accurate and delivered in real-time.
More often however, industrial professionals rely on comprehensive gauge systems with incorporated pressure transmitters to maintain optimal pressure levels for gas, oils, and high temperature liquids.
Gauge Pressure Transmitters
Gauge pressure transmitters are equipped for absolute pressure measurements with industry-specific considerations to support severe process monitoring. Steel diaphragms fitted to pressure vessels or pipework can register minute deformations relating to applied force, which is in turn swiftly translated into an electrical signal by a pressure sensor within the gauge transmitter. This can be measured remotely, or monitored through intuitive, user-friendly displays at the site of measurement.
Applications of Pressure Transmitters
Pressure transmitters are routinely used in a wide range of industrial sectors. Offshore drilling and oil exploration commonly utilize pressure sensors to measure differential values between the interior and exterior of pressure sensitive equipment. Distinct parameters must be maintained to ensure drilling and acquisition processes are carried out to an ethical and efficient standard. This is also true of on-shore petrochemical, gas, and chemical facilities.
Numerous industries use pressure-sensitive transportation and storage devices to maintain optimal product conditions, which must be accurately monitored to ensure safe delivery and eventual application. Laboratories also use pressure sensors to measure the relative pressure of vacuum chambers to the atmosphere, supporting a limitless range of emerging studies.
Pressure Transmitters from ABB
ABB is a leading developer of measurement instrumentation for industrial and research applications, with an established range of pressure sensors suitable to everyday and cutting-edge applications. With All-Welded technologies, automatic on-board configuration, and enhanced plug and play graphical interfaces, measuring pressure can be a safe and seamless process.
Pressure Sensor Types: Piezoresistive Sensors Pressure Measuring Methods
Whether you are new to the technology or have worked with pressure sensors for years, how confident are you with some of the terminology involved in pressure sensor selection? Today I will provide a refresher on the common terminology you will be exposed to during your quest to spec the best pressure sensor for your application.
With a growing pressure sensor market and an increase in applications for the technology, as an engineer you are bound to work with pressure sensors if you haven’t already. A recently published Zion Research report on the market estimates the global demand for pressure sensors to reach USD 9.5 billion by 2020, up from USD 6.5 billion in 2014. The key markets for pressure sensors are automotive, consumer electronics, industrial, medical, and oil gas, though the application of this technology is ever-expanding.
As pressure sensors become increasingly prevalent, it is important for engineers to know the basic terminology for product selection. Let’s review some of the common terms and questions related to selecting a pressure sensor.
How Does a Pressure Sensor Work? Piezoresistive Sensors
The most common type of pressure sensor for general purpose detection uses a diaphragm made of silicon or stainless steel (for harsher applications) as a strain gauge, meaning a flexible material designed to deflect in proportion to the amount of applied pressure. That deflection is a measured value that is converted into an electrical signal the sensor can interpret. When taking a deeper technical dive into how the sensing element works, you may hear reference to piezoresistive type pressure sensors. Piezo comes from the Greek word “piezein,” which means “squeeze” or “apply some pressure.” The piezoresistive effect is the change in electrical resistance of a semiconductor material due to mechanical stress across the piezo material, or diaphragm. Piezoresistive sensors convert the mechanical energy from the deflected diaphragm into proportionate levels of resistance, unlike their cousin the piezoelectric sensor, who converts the stimulus to a charge or voltage. Piezoresistive sensors are typically available in a wider variety of packaging options and specify abilities greater than 10 mV/V. An example of a piezoresistive pressure sensor is the 33A-015D from TE Connectivity.
