Pressure Sensors: Monitoring Critical Systems

What are Pressure Sensors?

Pressure sensors are devices that detect and measure the force exerted by a liquid or gas on a surface, converting it into an electrical signal proportional to the pressure applied. These are crucial in systems requiring accurate pressure monitoring, such as those found in automotive manufacturing, medical ventilators, Heating, Ventilation, and Air Conditioning (HVAC) systems, and other high-precision industrial settings.

How They Work

The earliest documented pressure measurement device was the mercury barometer, invented by Evangelista Torricelli in 1643. This was very helpful for practical applications, such as pumping water, measuring atmospheric conditions, and controlling steam engines.

While both ancient manometers and 21st-century electronic gauges detect pressure-induced physical changes, the modern Internet of Things (IoT) sensors instantly convert those changes into readable signals.

Electronic pressure sensors of the 21st century operate on the same principle: they detect physical changes within a space caused by force. The main difference is that the results of automated gauges are immediately converted into readable signals. These enable more precise control, monitoring, and integration into digital systems across various industries. Here is a step-by-step summary:

Mechanism of Pressure Sensors

1. Pressure causes a mechanical deformation, such as the bending of the diaphragm.

2. The deformation changes the electrical property.

3. The sensor converts the electrical change into a signal.

4. The signal is read and displayed as a pressure measurement.

5. The data may be sent to a Computerized Maintenance Management System (CMMS), which alerts maintenance teams in case of abnormal levels or readings.

Common Types

Pressure sensors vary in shape and size to meet the demands of diverse applications, ranging from detecting minute changes in atmospheric pressure to managing high-pressure hydraulic systems. Get to know the most common types below:

1. Strain Gauge: This type measures pressure by detecting strain in a material due to applied force. Often, this is the pressure sensor of choice for hydraulic presses and hydrostatic level sensing in the automotive and aerospace sectors.

2. Piezoelectric: This quantifies dynamic pressure using piezoelectric crystals embedded in the sensor, which generate an electric charge when pressure changes rapidly, such as vibrations or shock waves. This type is used in dynamic pressure testing equipment, such as in engine diagnostics (automotive), ultrasound equipment (healthcare), and tire pressure sensors in new vehicles.

3. Capacitative: This measures pressure changes by detecting variations in capacitance between two plates (one fixed, one movable) attached to the diaphragm, with the flex altering the distance between the plates and translating it into an electrical signal. This type is used in air pressure sensors of HVAC controls and environmental monitoring systems.

4. Manometer: One of the most traditional types, this uses a column of fluid to measure pressure. Manometers are a common tool in laboratories for applications requiring low-pressure measurements.

5. Vacuum: Utilizing strain or piezoelectric elements, this sensor compares internal vacuum to ambient (negative) pressure. It is used in semiconductor manufacturing and vacuum pumps.

6. Bourdon Tube: Featuring a curved tube, this measures pressure as the tube straightens, driving a dial or output. It is the typical choice in steam boilers and mechanical gauges.

7. Aneroid Barometer: This employs a sealed metal chamber that expands and contracts with pressure, causing a needle to move. Unlike their fluid-based counterparts, aneroid barometers are well-suited for weather stations, aircraft altimeters, and hiking tools because they are more portable and durable.

Applications in Different Industries

Advancements in pressure sensor technology have revolutionized how industries monitor, control, and optimize systems. These upgrades not only enhance performance but also support safety, energy efficiency, automation, and compliance, making pressure sensors an indispensable tool in the following sectors:

Manufacturing

Traditional manual gauges were prone to human error and delayed readings. In contrast, modern digital sensors transmit real-time data, which facilitates predictive maintenance for the following:

• Monitoring leaks or blockages in hydraulic presses

• Measuring injection pressure to detect material inconsistencies in injection molders

• Monitoring lubrication and predicting failures in pneumatic actuators

• Detecting air pressure fluctuations in air compressors

• Monitoring steam or water pressure in boilers and heat exchangers

Construction

Using manual gauges can lead to costly damage and performance issues. Embedded sensors provide real-time data that allows engineers and property managers to proactively improve safety, streamline maintenance, and optimize resource use. Pressure sensors can help particularly with the following in construction:

• Detecting overpressure or pressure loss in hydraulic excavators and loaders

• Preventing line bursts in concrete pumping systems

• Verifying load distribution and maintaining structural stability of supporting systems and other temporary supports.

Healthcare

Past mechanical devices were bulky and lacked accuracy. Today, miniaturized, high-precision sensors provide real-time, wireless monitoring, dramatically improving healthcare outcomes for patients being monitored at home or after discharge. Examples of how medical pressure sensors work and improve wellbeing are the following:

• Mechanical ventilators monitor airway pressure, regulating airflow to the lungs.

• Infusion pumps detect line pressure, ensuring accurate fluid or drug delivery and alerting to potential blockages or occlusions.

• Sphygmomanometers (blood pressure monitors) can be used at home.

Automotive

Limited visibility into a car’s systems can lead to unexpected failures and higher repair costs. Digital pressure sensors address this by continuously transmitting data to the onboard computer, which makes real-time adjustments to improve performance and enhance driver safety. Some pressure sensors often used in the automotive industry are the following:

• Tire Pressure Monitoring Sensors (TPMS) alert drivers of low tire pressure before a flat or blowout occurs.

• Engine oil pressure sensors detect drops in oil pressure to prevent engine damage.

• Brake pressure sensors monitor brake system integrity for early signs of wear or leaks.

Environmental and Utility Management

Manual, on-site data collection made it difficult to respond to rapid changes. Today, however, sensors send data to the cloud for remote monitoring and automated alerts, helping with the following:

• Maintaining good indoor air quality by checking airflow direction and controlling contaminants

• Preventing overflows or low supply by measuring pressure at the bottom of a tank or reservoir

• Monitoring line pressure in gas pipelines to detect sudden drops or fluctuations

Benefits of Digital Pressure Sensor Solutions

Industries can no longer afford to rely on manual methods of pressure sensing. Precision, speed, and responsiveness are critical for operational efficiency, safety, and compliance. Digital solutions can help centralize these readings and data, making it easier for organizations to analyze them. One such platform is Mitti (by SafetyCulture), which aims to improve workflow operations for all industries. With digital checklists, asset tracking tags, and monitoring sensors for all uses, this platform can help organizations stay on top of its pressure readings easily, ensuring worker, client, and workplace safety.

For those without pressure sensors yet, Mitti (by SafetyCulture) also offers their own, such as Standard Air Pressure Differential Sensors. It is tailored for high-accuracy use in critical applications across healthcare, pharmaceutical, and manufacturing sectors. Be assured of sensor performance with guidance from Mitti (by SafetyCulture) monitoring experts, and watch existing monitoring practices improve in real time.

Here are some of the upsides of investing in Mitti (by SafetyCulture):

• Better real-time monitoring procedures – Track pressure changes to detect anomalies, preventing serious failures and subsequent hazards.

• Improved remote access and alerts – Gain 360-degree visibility and automated notifications to quickly respond to pressure-related issues online and offline, anytime, anywhere.

• More efficient historical analysis – Store trend reports, completed checklists and inspection forms, and analytical reports over time in the cloud for better diagnostics, predictive maintenance, and informed decision-making.

• More seamless integration with other systems – Seamlessly connect with IoT and building management systems in addition to pressure sensors for centralized control.

• Improved safety and compliance – Maintain pressure within safe thresholds, reducing risks and supporting regulatory compliance.

• Enhanced asset management practices – Keep an eye on pressure sensors and other equipment in use to ensure they’re in good working condition at all times.

• More efficient equipment – Minimize wear and tear by maintaining optimal operating conditions, delaying costly repairs and replacements.