A pressure gauge is an instrument used to measure the pressure of liquids and gases. It converts pressure into a directly readable value, enabling accurate monitoring of hydraulic systems, pneumatic lines, piping networks or storage vessels.
Origins & History The genesis of the pressure gauge traces back to Gasparo Berti’s vacuum experiment (1640–1643), in which he accidentally created a sealed glass tube to observe the balance between vacuum and atmospheric pressure. In 1643, Evangelista Torricelli refined this concept by inventing the first mercury barometer, laying the groundwork for atmospheric pressure measurement and weather forecasting.
Types of Pressure Gauges – U-Tube Manometer – Barometer (atmospheric pressure gauge) – Blood Pressure Monitor – Industrial Pressure Gauge (Bourdon tube, diaphragm or helical element) – Differential Pressure Gauge (measures the pressure difference between two points)
Principles of Operation
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U-Tube Manometer: Relies on the height difference between two liquid columns when one leg is exposed to the measured pressure. The column-height differential is proportional to the applied pressure.
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Barometer: Measures local atmospheric pressure. A classic mercury barometer consists of a sealed glass tube filled with mercury; as ambient pressure rises or falls, the mercury column correspondingly moves up or down.
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Mechanical Pressure Gauge: Typically uses a Bourdon tube whose elastic deformation drives a pointer across a dial to indicate relative or absolute pressure. These gauges are ubiquitous in hydraulic systems, pneumatic circuits, steam boilers, vacuum pumps and pressure-regulating equipment.
Common Pressure Units Pascal (Pa), bar, megapascal (MPa), pound-force per square inch (psi), kilogram-force per square centimetre (kgf/cm²), millimetre of mercury (mmHg). Unit selection depends on industry standards and regional conventions.
Selection Criteria
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Pressure type: absolute, gauge or differential
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Measurement range & accuracy requirements
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Process media properties: corrosiveness, viscosity, temperature
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Operating environment: vibration, shock, chemical exposure, extreme temperatures
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Mechanical connection: threads, flanges or hoses; display mode: analog or digital
Installation, Calibration & Maintenance
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Install the gauge with its dial visible at eye level; avoid high-vibration or extreme-temperature locations.
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Use snubbers or dampers to protect Bourdon tubes from pressure spikes.
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Perform zero-point calibration before commissioning (e.g. adjust the pointer to zero at ambient pressure).
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Ensure proper sealing of threads or flanges (PTFE tape or compatible gaskets) and verify leak tightness.
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Operate continuously below 75 % of full-scale to prevent permanent deformation.
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Recalibrate and inspect every 6–12 months: clean the window, replace gaskets, check fittings and re-certify if measurement error exceeds tolerance.
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Digital gauges often include Min/Max data logging and 4–20 mA outputs for integration with automation systems.
Applications – Medical (blood pressure measurement) – Energy (oil & gas pipeline monitoring) – Machinery manufacturing – Construction (concrete pressure testing) – HVAC (fan and pump pressure control) – Aerospace (cabin pressure monitoring, leak detection).
About QTE Technologies QTE Technologies offers a wide range of high-precision, durable pressure gauges from leading brands. As an international MRO supplier since 2010, we proudly serve customers in over 180 countries and have delivered more than one million products across industrial and scientific sectors. Our 24×7 support team is available via live chat, telephone, WhatsApp or email. Discover what our valued customers say on our dedicated review page.
Post Author By QTE Technologies Editorial Staff (with a solid background in both technical and creative writing - accumulated 15+ years of experience).
