Real‑world examples of pressure measurement in fluids

Lab‑grade examples of pressure measurement in fluids you actually use

Let’s start where most people first meet fluid pressure: the teaching lab. These are the classic examples of pressure measurement in fluids that show up in undergraduate fluid mechanics experiments.

Manometers: the go‑to example of simple, visual pressure measurement

A U‑tube manometer is probably the first example of pressure measurement in fluids you ever touched. It’s just a transparent U‑shaped tube, partly filled with a liquid (often water or mercury in older setups, colored alcohol or oil in modern labs). One leg is connected to a pressure source; the other is open to the atmosphere or a reference line.

The pressure difference is read directly from the height difference between the two columns using

\[ \Delta p = \rho g \Delta h \]

where \(\rho\) is the manometer fluid density, \(g\) is gravitational acceleration, and \(\Delta h\) is the height difference.

In teaching labs, examples include:

• Measuring pressure drop along a straight pipe to compare with the Darcy–Weisbach equation.
• Checking static pressure at a stagnation point versus a free stream to verify Bernoulli’s equation.
• Comparing two different working fluids (air vs. water) while using the same manometer liquid.

These are some of the best examples for demonstrating how pressure in fluids relates directly to depth and density, because you literally see the pressure difference as a height difference.

Inclined manometer: a more sensitive example of low pressure measurement

When pressure differences are small, a standard U‑tube can be annoyingly coarse. An inclined manometer stretches the same vertical change in height over a longer slanted tube, giving finer resolution.

In fluid mechanics experiments, an example of this in action is measuring:

• Tiny pressure differences across an airfoil in a wind tunnel.
• Pressure drop across a fine screen or porous medium.

Because the tube is inclined at a known angle, the vertical height change is the measured length times the sine of that angle. In other words, you get more readable data for very small changes—one of the best examples of how geometry can amplify measurement sensitivity without adding electronics.

Bourdon gauge: rugged example of mechanical pressure measurement

Move from the lab bench to industrial hardware and you’ll see Bourdon gauges everywhere: on air compressors, boilers, hydraulic power packs. A curved, hollow metal tube straightens slightly as internal pressure rises. That motion drives a pointer over a dial.

In experiments, examples include:

• Monitoring the discharge pressure of a centrifugal pump during a pump performance test.
• Checking inlet and outlet pressures on a heat exchanger.
• Verifying pressure in an air receiver tank before running a pneumatic experiment.

Bourdon gauges are not as precise as a good manometer, but they’re tough, cheap, and easy to read from a distance—perfect real examples of pressure measurement in fluids in noisy, messy environments.

Electronic and digital examples of pressure measurement in fluids

Modern labs and industrial systems increasingly favor electronic sensors. They feed directly into data acquisition (DAQ) systems, making it easier to log, analyze, and automate.

Strain‑gauge pressure transducers: workhorse example in research labs

A strain‑gauge pressure transducer uses a thin diaphragm that flexes under fluid pressure. Strain gauges bonded to the diaphragm change resistance as it deforms. An electronic bridge circuit converts that change into a voltage proportional to pressure.

In fluid mechanics experiments, examples of their use include:

• Measuring transient pressure spikes (water hammer) when a valve closes suddenly.
• Mapping pressure distribution along a pipe to detect friction losses and minor losses at fittings.
• Capturing rapid pressure fluctuations in turbulent jets or combustion research.

Because they can handle dynamic changes and interface with modern DAQ systems, they’re among the best examples of pressure measurement in fluids for time‑resolved, research‑grade work.

For a general overview of strain‑based sensing, the National Institute of Standards and Technology (NIST) offers background on measurement science and calibration practices: https://www.nist.gov.

Piezoresistive and MEMS sensors: compact examples for 2024‑era systems

Micro‑electromechanical systems (MEMS) pressure sensors have become standard in aerospace, automotive, and biomedical applications. A tiny silicon diaphragm flexes under pressure, changing the resistance of implanted piezoresistors.

Recent 2024–2025 trends show:

• Widespread use in automotive tire pressure monitoring systems (TPMS).
• Integration into consumer devices for altitude and weather estimation.
• Miniaturized catheter‑tip pressure sensors in medical diagnostics.

In fluid mechanics experiments, real examples include:

• Measuring pressure inside microfluidic channels for lab‑on‑a‑chip research.
• Monitoring pressure in small‑scale wind tunnel models where space is limited.

These are excellent modern examples of pressure measurement in fluids where size and power consumption matter as much as raw accuracy.

Differential pressure transmitters: classic example of flow‑related pressure measurement

Differential pressure (DP) transmitters compare pressure between two points and output a signal proportional to the difference. Pair one with a constriction like an orifice plate or Venturi tube, and you have a flow meter.

In both teaching and industrial labs, examples include:

• Measuring flow rate in a water loop using a Venturi meter and a DP transmitter.
• Monitoring filter fouling by tracking pressure drop across a filter housing.
• Checking performance of HVAC duct systems by measuring static vs. total pressure.

Because flow rate is proportional to the square root of the measured pressure difference, these setups are textbook examples of pressure measurement in fluids being used indirectly to infer another quantity.

The U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy discusses flow measurement and efficiency in industrial systems: https://www.energy.gov/eere.

Everyday real examples of pressure measurement in fluids

Not every experiment lives in a lab. Some of the clearest examples of pressure measurement in fluids are things you see in daily life.

Blood pressure measurement: a biomedical example of fluid pressure

A blood pressure cuff (sphygmomanometer) is a perfect real‑world example of pressure measurement in a biological fluid. The cuff inflates around your arm, squeezing the artery until blood flow stops. As the cuff slowly deflates, a gauge (often electronic, sometimes aneroid) tracks the pressure at which blood flow resumes and becomes laminar again.

Here, the fluid is blood, and the measurement is in millimeters of mercury (mmHg). Systolic and diastolic pressures are interpreted using long‑established clinical guidelines. For medically oriented readers, the National Heart, Lung, and Blood Institute (NHLBI) at NIH provides detailed information: https://www.nhlbi.nih.gov.

In a fluid mechanics context, this is an elegant example of using pressure in a compliant, pulsatile system to infer cardiovascular health.

Tire pressure gauges: simple but powerful example of gas pressure measurement

Check your car tire pressure and you’re performing one of the most common examples of pressure measurement in fluids—in this case, a gas. Whether you use a stick gauge, dial gauge, or digital gauge, the principle is the same: the internal air pressure pushes against a sensing element, which translates that force into a reading.

From a fluid mechanics perspective, this is a neat applied example of how maintaining correct pressure affects contact area, rolling resistance, and heat buildup. It’s also a reminder that fluids include both liquids and gases, and examples of pressure measurement in fluids are not limited to water‑based systems.

Weather and aviation: barometers and altimeters as atmospheric examples

Barometers measure atmospheric pressure, a key variable for weather forecasting. Mercury barometers are the classic lab example of a static fluid column balancing atmospheric pressure; aneroid barometers use a sealed, flexible capsule.

Aircraft altimeters are essentially barometers calibrated to report altitude instead of pressure. The pressure measurement is still fluid pressure—just in a very large, low‑density fluid: the atmosphere.

These are good real examples of pressure measurement in fluids at large spatial scales, connecting directly to meteorology and aerodynamics.

Advanced and industrial examples of pressure measurement in fluids

Beyond teaching labs and everyday devices, there are more specialized examples of pressure measurement in fluids that show up in industry and research.

Hydrostatic level measurement in tanks

If you know the density of a liquid, you can measure its pressure at a known depth and convert that directly to level. A pressure sensor mounted near the bottom of a tank reads the hydrostatic pressure from the liquid column above it.

Examples include:

• Monitoring water level in municipal storage tanks.
• Measuring fuel level in large storage tanks at refineries.
• Tracking chemical levels in process vessels in a plant.

This is a practical example of pressure measurement in fluids that turns a simple pressure reading into volume or mass inventory data.

Downhole and subsea pressure sensors

Oil and gas operations use high‑pressure sensors in wells and subsea pipelines. These sensors must survive extreme pressures, temperatures, and corrosive fluids.

Real examples include:

• Measuring formation pressure thousands of feet below the surface to assess reservoir behavior.
• Monitoring pressure in subsea pipelines to detect leaks or hydrate formation risk.

These are demanding examples of pressure measurement in fluids where reliability and long‑term stability are more important than the last decimal place of accuracy.

Cavitation and pump testing in fluid mechanics labs

In pump test rigs, pressure taps are installed at the pump inlet and outlet, connected to either manometers or electronic transducers. By varying suction conditions, researchers can determine the net positive suction head (NPSH) and identify when cavitation begins.

Here, examples of measurements include:

• Inlet absolute pressure to compare with vapor pressure of the liquid.
• Discharge pressure to calculate pump head and efficiency.

These experiments are some of the best examples of pressure measurement in fluids directly informing design limits: push the pump too far, and the pressure profile tells you exactly when and where vapor bubbles start to form.

How to choose between different examples of pressure measurement in fluids

If you’re designing an experiment or a lab setup, the right choice depends on:

• Pressure range: Manometers work well for low to moderate pressures; Bourdon gauges and transducers cover higher ranges.
• Fluid type: Corrosive or dirty fluids may require isolation diaphragms or remote seals.
• Dynamic vs. static: For steady, static readings, manometers and Bourdon gauges are fine. For fast transients, strain‑gauge or piezoelectric transducers are better examples of suitable solutions.
• Required accuracy and resolution: Inclined manometers and calibrated electronic sensors win here.
• Data needs: If you need digital logging, plotting, or control, electronic sensors integrated with DAQ hardware are the most practical examples.

In a teaching lab, pairing a simple manometer with an electronic transducer on the same line is a smart move. Students see both the visual height difference and the digital signal, making the physics and the electronics line up.

FAQ: common questions about examples of pressure measurement in fluids

Q1: What are the most common examples of pressure measurement in fluids used in undergraduate labs?

The most common examples include U‑tube and inclined manometers, Bourdon gauges on pumps and compressors, and basic electronic strain‑gauge pressure transducers tied into a DAQ system. Together they cover low‑pressure, moderate‑pressure, and dynamic measurements in both liquids and gases.

Q2: Can you give an example of using pressure measurement to determine flow rate?

Yes. A classic example of pressure measurement in fluids used to determine flow is an orifice plate or Venturi meter installed in a pipe. A differential pressure transmitter measures the pressure drop between upstream and throat sections. Using Bernoulli’s equation and a discharge coefficient, you convert that pressure difference into volumetric or mass flow rate.

Q3: What are some real examples of pressure measurement in fluids in everyday life?

Real examples include blood pressure cuffs, tire pressure gauges, home weather barometers, and the pressure sensor in your car’s TPMS. All of these rely on the same basic idea: fluid pressure exerts a force on a surface, and that force is turned into a readable signal.

Q4: Why are manometers still used when electronic sensors exist?

Manometers remain popular because they’re simple, inexpensive, and inherently calibrated by gravity and fluid density. They’re excellent reference standards and teaching tools. In many labs, they act as a sanity check for electronic sensors, providing a straightforward visual example of pressure measurement in fluids.

Q5: How are high‑pressure measurements handled safely in experiments?

High‑pressure experiments use rated fittings, relief valves, and sensors designed for the expected range with safety margins. Often, the sensing element is isolated from the process fluid using a diaphragm seal and fill fluid. Proper design follows standards and best practices outlined by organizations like ASME and is supported by calibration labs such as those referenced by NIST.