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.
Pressure Transducers and Water Pipe Pressure Measurement
Water pressure transducers also called a water pressure sensor,
are pressure transmitters that can measure water pipe pressure.
For the water level/water depth measurement,
in the tank, or in the well, we can use electrical transmitters, stainless steel body, IP65-IP6, 4-20ma output.
Sino-Inst applies application expertise to design and manufacture pressure sensors and transducers for the water industry.
Various factors impact the selection and long term use of water pressure sensors and transducers, in residential, commercial, and irrigation systems.
Sino manufactures various products with design features, to offer excellent accuracy and long term stability.
Below is some basic information to review, before making a decision on the type of pressure sensor technology, as well as the electrical and mechanical features required.
A pressure sensing element will come in contact with varying pH levels, depending on the type of water, chemicals added, and the quality of the water purification process.
Sino packages pressure sensors using silicon strain gages, mounted onto a one-piece, 316L stainless steel sensing element.
316L SS offers excellent media compatibility for residential, and commercial water applications and is an NSF61 compliant material.
Environment
Rain, ice, dust, and pressure washers can cause water to seep into sensor housings, and cause the electronics to short.
Sino offers sealed gauge reference pressure sensors to protect the electronics from these conditions.
Electrical Isolation
Improper grounding and lightning strikes can cause electrical failures of pressure sensors, as a result of isolation failure.
Sino can include custom electronics and a sensing element to withstand 500VDC isolation to work in extreme electrical conditions.
The use of a 4-20mA output signal for transmission lengths greater than 15 feet in environments with electrical noise, will help prevent signal loss or noisy signal conditions.
Sanitary sensors
Sanitary Sensors that Deliver Accurate Data in Food and Pharma Industries
Having access to accurate pressure and temperature readings at all times is essential in hygienic processing environments such as the food and pharmaceutical industries. Regulatory requirements demand 24/7 product monitoring as well as extensive documentation of quality control processes.
Accomplishing this task means having accurate, reliable pressure, temperature and level measurement instruments in your production facilities, and setting up network infrastructure to support, and distribute and retain the data.
WIKA offers a complete line of accurate and reliable sanitary sensors, including a variety of pressure and level transmitters and a range of electrical thermometer and temperature transmitters that have been designed exclusively for hygienic applications and meet 3A and EHEDG approvals.
Sanitary Sensors for Pressure and Level Measurement
WIKA Models IPT-10 and IPT-11
WIKA model IPT-10 and IPT-11 sanitary sensors are designed for use in the pharmaceutical, and food and beverage sectors. Available with a standard hygienic fitting or a flush diaphragm, these sanitary pressure sensors can be ordered with metallic or ceramic measuring cells in seven different housing variants. The transmitters are configured with a Device Type Manager (DTM) as a Field Device Tool (FDT).
WIKA Models UPT-20 and UPT-21
WIKA model UPT 20 and 21 sanitary sensors are commonly used in pharmaceutical, cosmetic, beverage and food industries. This type of pressure transmitter can be easily converted to meet hygienic standards by adding an applicable industry standard sanitary diaphragm seal. These sanitary sensors feature a large, rotatable multi-functional display, and easy, intuitive menu navigation.
WIKA Model SA-11
WIKA SA-11 sanitary sensors are certified to meet all 3A and EHEDG standards for pressure and level measurement in the food, pharmaceutical, biotechnology, and cosmetic industries. These devices are designed for temperatures up to 300°F and are available in 1.5" and 2" Tri-Clamp® process connections, while offering 0.25% accuracy. The applied technology allows a full scale measuring span down to 100 inches of water column.
WIKA Model S-10-3A
The model S-10-3A sanitary pressure transmitter is designed for use in the food and beverage, pharmaceutical, and cosmetic sectors. This sanitary sensor is 3A compliant and is available with a 3/4", 1.5" or 2.0" Tri-Clamp® process connection. An integral cooling extension element can also be added for high or low temperature applications.
WIKA Model DPT-10
WIKA’s DPT-10 provides differential pressure measurement for applications in the pharmaceutical, biotechnology, and food and beverage industries. This highly accurate pressure sensor features scalable measuring ranges, seven different housing variants, and meets or exceeds a variety of standards for use in hazardous areas. These differential pressure transmitters are configurable using a Device Type Manager (DTM) as a Field Device Tool (FDT).
Capacitive Elements
The modeling and characterization of capacitive elements with tissue as the dielectric material, representing the core building block of a capacitive link for wireless power transfer to neural implants. Each capacitive element consists of two parallel plates that are aligned around the tissue layer and incorporate a grounded, guarded, capacitive pad to mitigate the adverse effect of stray capacitances and shield the plates from external interfering electric fields. The plates are also coated with a biocompatible, insulating, coating layer on the inner side of each plate in contact with the tissue. A comprehensive circuit model is presented that accounts for the effect of the coating layers and is validated by measurements of the equivalent capacitance as well as impedance magnitude/phase of the parallel plates over a wide frequency range of 1 kHz-10 MHz. Using insulating coating layers of Parylene-C at a thickness of 7.5 μm and Parylene-N at a thickness of 1 μm deposited on two sets of parallel plates with different sizes and shapes of the guarded pad, our modeling and characterization results accurately capture the effect of the thickness and electrical properties of the coating layers on the behavior of the capacitive elements over frequency and with different tissues.
