What Is a Pressure Sensor?

Ultimate Guide to Pressure Sensors

Pressure measurement involves measuring the force applied by a fluid (liquid or gas) on a surface. This is often expressed as force per unit of surface area.

This process is integral to modern technology, and instruments used for pressure measurement are called pressure sensors. These sensors transform pressure into electrical signals.

Pressure sensors are used in various applications ranging from industrial automation to healthcare. Yet, not many people understand what they are and how they work.

In this blog post, we cover everything you need to know about pressure sensors including:

• What they are
• How they work
• Uses and applications
• Different types of pressure sensors

What are Pressure Sensors?

A pressure sensor is a device that measures the pressure of gases or liquids, converting it into an electrical signal.

This signal is then processed and transmitted to control systems or monitoring equipment. Pressure sensors play a crucial role in applications such as regulating processes, monitoring storage tanks, studying weather, and assessing medical conditions.

Pressure sensors, often measuring additional variables like temperature or flow rate, provide essential data for monitoring and control purposes by translating physical force into electrical signals.

Related: What is Pressure Measurement?

How Do Pressure Sensors Work?

Pressure sensors work by using different principles, such as the piezoelectric effect or strain gauges. When a force is applied, it causes physical changes that result in an electrical output signal.

Each type of pressure sensor has its unique mechanism for measuring pressure and often incorporates sensitive elements for accurate readings.

The fundamental working principle involves the sensing element reacting to applied pressure, triggering the production of an output voltage.

These values can then be conditioned, adjusted for environmental factors, and transmitted as analogue or digital signals, enabling continuous monitoring of applied pressure over time.

Our team at Process Parameters has extensive knowledge and experience in temperature management and process control. 

Browse our pressure sensors, submersible level transmitters and level sensors. If you have any questions, please get in touch. 

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Industrial Uses for Pressure Sensors

The use of a pressure sensor depends on its type and the intended function. However, typical examples of industrial pressure sensor applications may involve:

• Flow Monitoring – Pressure sensors are extensively used to measure flow rates and velocities of liquids, gases, and steam in pipelines and ductwork. They allow for optimising flows and prevent overload conditions.
• Level Measurement – Measuring changes in hydrostatic pressure at the bottom of a tank correlates precisely to fluid level height, enabling accurate level monitoring. This helps prevent overfills or running dry.
• Altitude and Draft Sensing – As air pressure changes predictably with altitude, pressure sensors serve as the basis for nearly all aircraft and drone altimeters for navigation and drafting.
• Leak Detection – Pressure sensors detect abnormal pressure drops within pipes, tanks and other vessels that indicate a potential breach or leak, allowing timely repairs.
• Valve Control – By tying into system pressure change dynamics, sensors allow accurate controlling valve open percentages to govern desired flow rates.
• Condition Monitoring – Deviation from expected pressure profiles helps diagnose emerging issues with pumps, compressors, blowers and other machinery before outright failure.
• Weather Compensation – Measuring real-time barometric pressure aids equipment in compensating for weather changes that influence flows, filling, pressure differentials and calibration.

The Difference Between Pressure Transducers, Transmitters and Sensors

Before examining pressure sensor types, it helps to clarify key terminology differences, as these terms get used interchangeably.

All three technologies utilise a sensing element that physically reacts to pressure changes. This reaction requires translation into electronic signals and conditioning before systems interpret the data.

Pressure sensors provide a raw voltage output based solely on physical sensor reactions, therefore requiring extensive downstream processing externally.

Pressure transducers also convert internal reactions into voltage outputs, but integrate some signal conditioning like amplification, calibration and temperature compensation internally, enabling transmission over longer distances.

Pressure transmitters work similarly, but output a standardised current signal across an electrical loop compatible with industrial equipment, typically 4-20mA.

Types of Pressure Sensors

Pressure sensors come in an array of types, each tailored for specific applications. Matching pressure sensor type capabilities to intended uses and output requirements is essential for optimal performance.

Let’s explore the various types of pressure sensors in more detail.

Absolute Sensors

An absolute sensor measures pressure relative to a perfect vacuum, disregarding atmospheric pressure. It starts from zero pressure, making it suitable for applications like altimeters and vacuum systems.

This type of sensor is essential where an accurate zero pressure reference is crucial, providing precise readings independent of atmospheric fluctuations.

Differential Sensors

A differential sensor measures the pressure difference between two points, providing insights into changes in pressure.

Commonly used in applications where the relative pressure between two locations is critical, these sensors are valuable in scenarios such as flow measurements, filter monitoring, and pressure drop assessments in various industrial and scientific processes.

Gauge Pressure Sensors

Gauge pressure sensors, often based on strain gauge principles, measure pressure by detecting the deformation caused by applied pressure.

They excel in applications requiring high accuracy and sensitivity, providing precise readings for low pressures, fluid pressure, and liquid level measurements.

Widely used in industrial and environmental contexts, these sensors generate an output signal proportional to the applied pressure, enabling accurate measurements and informed corrective actions.

Piezoelectric Pressure Sensors

Piezoelectric sensors generate electrical charges in response to mechanical stress, offering rapid response times. They are suitable for dynamic pressure measurements in challenging environments.

These sensors use the piezoelectric effect to gauge pressure by producing an electric charge, finding applications in various industrial settings for precise and responsive pressure readings, especially in dynamic and fluid pressure scenarios.

Capacitive Pressure Sensors

Capacitors store electric charge with two conductors separated by a narrow gap. Capacitive pressure sensors measure the capacitance between these plates, varying with surrounding pressure.

Used in jet engines, car tires, and vessels, their robust, simple design allows resilience in harsh environments.

Manometer Pressure Sensors

Manometers, essentially liquid-filled tubes, compare pressure on two surfaces using liquid movement. Basic manometers, like U-shaped ones, use liquid displacement to gauge pressure differences.

Although still used for calibration in labs, their slower response and limited pressure range make them unsuitable for dynamic sensing applications.

Bourdon Tube Pressure Sensors

Bourdon tube pressure sensors are common in industrial gauge pressure measurement. They operate by responding to the physical deformation of a curved tube when pressure is applied, producing an output signal corresponding to the pressure reading.

Widely employed in hydraulic systems and fluid level measurement, these sensors are vital components in pressure gauges and industrial machinery, contributing significantly to process control systems.

Aneroid Barometer Pressure Sensors

An aneroid barometer is a mechanical device for pressure measurement, featuring an airtight metal capsule that compresses and expands with surrounding pressure changes. These variations are measured and displayed on a dial, providing pressure readings.

Commonly used for atmospheric pressure measurement, aneroid barometers, known for their durability and convenience, find applications in aircraft. Additionally, they can measure altitude based on barometric pressure changes in aviation contexts.

Key Considerations in Pressure Sensor Selection

Choosing the right pressure sensor is crucial for optimal performance in any application. Here are key considerations to guide your selection process:

1. Pressure Range

Determine the operating pressure range of your application and select a sensor that can accurately measure within that range.

2. Accuracy and Precision

Different applications demand varying levels of accuracy. Evaluate the specifications of pressure sensors to ensure they align with your precision requirements.

3. Environmental Applications

Consider the environmental factors such as temperature, humidity, and exposure to chemicals. Select sensors with appropriate sealing and protection for reliable operation.

At Process Parameters, our team can help you select the best device for your application. Get in touch with our experts for more information.

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Applications of Pressure Sensors

Pressure sensors play a crucial role in various industrial applications, helping to measure and monitor pressure levels in different processes.

Here are some common industrial applications for pressure sensors:

1. Manufacturing and Process Control:
   • Pressure sensors are used in manufacturing processes to monitor and control the pressure of fluids or gases. This ensures that the manufacturing environment is optimised for efficiency and product quality.
2. Automotive Industry:
   • Pressure sensors are employed in automotive applications for measuring tire pressure, engine oil pressure, and fuel pressure. They contribute to vehicle safety, fuel efficiency, and overall performance.
3. Aerospace Industry:
   • In the aerospace sector, pressure sensors are utilised in aircraft and spacecraft for monitoring cabin pressure, fuel systems, hydraulic systems, and altitude. They are critical for ensuring the safety and functionality of these vehicles.
4. Medical Devices:
   • Pressure sensors are integrated into various medical devices such as ventilators, infusion pumps, and blood pressure monitors. They enable accurate and real-time monitoring of pressure levels, ensuring patient safety and treatment efficacy.
5. Oil and Gas Industry:
   • Pressure sensors are widely used in the oil and gas industry to monitor pipeline pressures, wellhead pressures, and various processes involved in exploration, extraction, and refining.
6. HVAC Systems:
   • Heating, Ventilation, and Air Conditioning (HVAC) systems utilise pressure sensors to monitor and control air and fluid flow. This helps in maintaining optimal environmental conditions in buildings.
7. Water and Wastewater Management:
   • Pressure sensors play a crucial role in water treatment plants and wastewater management systems. They monitor pressure levels in pipelines, tanks, and pumping stations, ensuring efficient and reliable operation.
8. Food and Beverage Industry:
   • Pressure sensors are used in the food and beverage industry to monitor and control processes such as bottling, packaging, and fermentation. They contribute to maintaining quality and consistency in production.
9. Pharmaceutical Manufacturing:
   • In pharmaceutical manufacturing, pressure sensors are employed to monitor and control various processes, including the production of drugs and the handling of chemicals. This ensures the precision and safety of pharmaceutical production.
10. Environmental Monitoring:
    • Pressure sensors are used in environmental monitoring systems to measure atmospheric pressure and weather conditions. They contribute to weather forecasting and research.

Pressure Sensors from Process Parameters

Pressure sensors play a crucial role in various industries and applications, revolutionising the way we measure and monitor pressure.

From optimising efficiency by regulating fluid and gas pressures in manufacturing to maintaining airflow control in HVAC, pressure sensors are versatile and essential tools.

At Process Parameters, we offer a range of pressure sensors suited to a range of industries. Unsure which sensor is best suited for your application? Get in touch with our expert team who will be happy to help you find the right product for your requirements and specifications.

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FAQs

What is a Pressure Sensor and How Does it Work?

A pressure sensor is a device that measures pressure and converts it into a readable output, often in the form of an electrical signal. It works by detecting the physical force exerted on it and then translating that force into a measurable value, usually using a diaphragm or a strain gauge.

What are Pressure Sensors Used For?

Pressure sensors are widely used in various industries, including automotive, aerospace, and environmental monitoring. They play a crucial role in medical devices, HVAC systems, and industrial equipment. Additionally, pressure sensors are essential for measuring fluid, gas, and liquid levels across different sectors. Their versatility extends to pressure transducers, transmitters, and various sensor applications, ensuring safety and efficiency.

How Are Pressure Sensors Revolutionising Industries?

Pressure sensors are revolutionising industries through their precision and reliability. They enable real-time monitoring of pressure variations, facilitating automation and enhancing industrial efficiency. Integrated into equipment, they ensure accurate pressure measurement, optimising manufacturing processes.

How Accurate are Pressure Sensors?

Pressure sensors can have a high level of accuracy, typically ranging from 0.1% to 1% of the full-scale pressure range. Factors that can affect their accuracy include temperature variations, sensor ageing, and external interference.

Regular calibration and maintenance can help maintain accuracy over time.

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• What is Pressure Measurement?
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