Pressure gauges and pressure sensors
Pressure gauges and pressure sensors play a vital role in safety, quality control, and regulatory compliance. A pressure gauge is a mechanical device that provides a local visual indication of pressure via a pointer on a dial, and typically includes Bourdon tube, diaphragm, and bellows gauges for a variety of pressure ranges and media. In contrast, pressure sensors (also known as transmitters) utilize principles such as piezoelectric, strain gauge, capacitance, and resonance effects to convert pressure into an electrical signal for remote monitoring and automated control systems. Pressure gauges provide simple and intuitive on-site readings, while sensors offer higher accuracy, faster response, and a variety of output signals (e.g., 4-20 mA, digital signals) for integration with modern control systems. Both require careful consideration of material compatibility, pressure and temperature ranges, and hazardous area certifications for chemical plant applications.
| Device type | Classification method | Features | Application scenario |
| Elastic element pressure gauge | Classification by measurement principle | Pressure is measured by the principle that elastic elements (such as spring tubes, bellows, diaphragms, etc.) undergo elastic deformation under pressure. Elastic element pressure gauges have simple structures, low costs, and wide measurement ranges. | It is widely used in chemical, petroleum, electric power and other industries to measure the pressure of liquids and gases. |
| Liquid column pressure gauge | Classification by measurement principle | The relationship between the height of the liquid column and the pressure is used to measure the pressure. Common liquid column pressure gauges include U-tube pressure gauges and single-tube pressure gauges. | It is suitable for measuring lower pressure ranges (such as 0-0.1 MPa) and is often used in laboratories and small-scale production. |
| Electrical pressure gauge | Classification by measurement principle | Convert pressure into electrical signals (such as voltage, current) for measurement and display. Common electrical pressure gauges include resistance, inductance, capacitance, etc. | Applicable to occasions requiring long-distance transmission and automatic control. |
| Strain pressure sensor | Classification by measurement principle | Measures pressure by using the principle that the resistance strain gauge is strained under pressure, resulting in a change in resistance value. Strain gauge pressure sensors have high precision and good stability. | Widely used in industrial automation, aerospace and other fields. |
| Piezoresistive pressure sensors | Classification by measurement principle | Pressure is measured by the principle that the resistivity of semiconductor materials changes under pressure. Piezoresistive pressure sensors have high sensitivity and fast response speed. | Suitable for occasions that require high precision and fast response, such as automotive electronics, medical equipment, etc. |
| Capacitive pressure sensor | Classification by measurement principle | Measures pressure by using the principle that the distance between capacitor plates or the area of plates changes under pressure. Capacitive pressure sensors have high accuracy and good linearity. | Suitable for high-precision pressure measurement, such as meteorological instruments, precision instruments, etc. |
| Piezoelectric pressure sensor | Classification by measurement principle | Measures pressure by using the principle that piezoelectric materials generate electric charges under pressure. Piezoelectric pressure sensors have fast response speed and good dynamic performance. | Suitable for dynamic pressure measurement, such as impact pressure, vibration pressure, etc. |
| Hall pressure sensor | Classification by measurement principle | Use the Hall effect to indirectly measure pressure by measuring changes in the magnetic field. Hall pressure sensors have a simple structure and low cost. | Suitable for general pressure measurement, such as industrial automation systems. |
| References | Authors | Abstract | DOI |
| Common Problems and Solutions of Chemical Pressure Gauge Measurement Verification | Mai Jiali | At present, all chemical enterprises in my country have realized mechanized production, and the scope of use of pressure gauges has been further expanded. The measurement verification of pressure gauges is mainly to ensure the accuracy of pressure, and accurate reference standards should be selected during operation. Based on this, the measurement verification of pressure gauges has also received widespread attention. This article analyzes the operation methods of pressure gauge metrological verification, points out common problems, and proposes relevant solutions, in order to provide more reference for future metrological verification work. | CNKI:SUN:SDHW.0.2018-01-032 |
| Technical analysis of the correct use of pressure gauges on chemical equipment | Jiang Shaoliang | This article takes the explosion accident of a pressure gauge in a chemical plant as an example and analyzes the cause of the explosion from a technical perspective. It points out that the pressure gauge is a very common simple automatic instrument widely used in chemical plants. Its correct use and selection are often more important than its manufacturing and should not be ignored. It also points out the precautions for selecting a pressure gauge when measuring the pressure of hazardous gases and the measures for correct use. | CNKI:SUN:ZDYB.0.1982-02-005 |
| Pressure gauge calibration and common problem handling | Du Shuyan | Pressure gauge is a commonly used measuring tool in industry and scientific research, mainly used to measure the pressure of liquid, gas and steam, or to measure vacuum. The elastic element inside the pressure gauge is a sensitive element. During the use of the pressure gauge, due to various reasons, the pressure gauge often fails, resulting in inaccurate measurement results. To this end, this article studies and discusses the common methods in the calibration and use of pressure gauges, and proposes treatment measures to provide reference and help for technicians in the maintenance of pressure gauges. | 10.3969/j.issn.1674-5167.2019.08.193 |
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