How is the Pressure in a Bourdon Tube Gauge Measured?
A Bourdon tube gauge is an instrument used to measure pressure, commonly employed in industrial applications. Unlike the diaphragm gauge, a Bourdon tube gauge consists of a curved tube filled with a liquid such as oil or water. The pressure exerted on the tube causes it to deform, indicating the pressure value. In this article, we will take a closer look at how a Bourdon tube gauge works and explain how pressure is measured in a Bourdon tube gauge.
How a Bourdon Tube Gauge Works
A Bourdon tube gauge consists of a curved tube, typically made of metal or plastic. The tube is filled with an incompressible liquid, such as oil or water. Each end of the tube has a connection that is attached to the system being measured.
When pressure is applied to the tube, it deforms and changes the position of the liquid inside. This deformation causes the tube to become slightly longer at one end and slightly shorter at the other end. This deformation is referred to as a "U-shaped tube bend." The deformation of the tube is proportional to the pressure applied to the tube. Therefore, the pressure value can be measured based on the position of the liquid in the tube.
Pressure Measurement
Measuring pressure in a Bourdon tube gauge involves several steps to ensure that the measurement is accurate and precise. Here are the steps required to measure the pressure in a Bourdon tube gauge:
Adjusting the Scale
The Bourdon tube gauge has a scale that displays the measured pressure. It is important to ensure that the scale is set to the correct range to ensure accurate measurement. Some Bourdon tube gauges have an adjustable scale, while others have a fixed scale.
Calibrating the Gauge
It is important to calibrate the Bourdon tube gauge before use to ensure it provides accurate readings. Calibration involves comparing the gauge to a known standard. If the gauge is not correctly calibrated, it can lead to incorrect readings.
Connecting the Gauge
The Bourdon tube gauge must be connected to the system being measured. The connections must be tightened to prevent any fluid leakage and to ensure the gauge functions correctly.
Removing Air Bubbles
It is important to ensure that there are no air bubbles in the fluid of the gauge. Air bubbles can lead to measurement errors. To remove air bubbles, the gauge should first be positioned vertically, and the fluid should be slowly and carefully poured into the tube. If air bubbles are present in the gauge, they can be removed by tapping the gauge or gently tilting it.
Reading the Measurement
Once the gauge is connected and bled, the measurement can be read. The position of the fluid in the tube indicates the pressure applied to the tube. The measurement is usually given in the unit of the system being used, such as psi, bar, or Pa.
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Advantages |
Disadvantages |
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Accuracy: Bourdon tube gauges offer high accuracy in pressure measurement. This is due to the direct measurement of pressure through the deformation of the tube.
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Limited Measurement Range: Bourdon tube gauges have a limited measurement range and may not be suitable for higher pressures and temperatures.
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Durability: Bourdon tube gauges are durable and reliable due to their robust construction and lack of moving parts.
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Sensitivity: Bourdon tube gauges can be sensitive to vibrations and shocks, which can lead to incorrect readings.
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Wide Range of Applications: Bourdon tube gauges are available in various sizes and configurations and can be used in many applications.
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Fluid Evaporation: Bourdon tube gauges can evaporate the fluid inside the tube at high temperatures, leading to incorrect readings.
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Low Cost: Bourdon tube gauges are relatively inexpensive compared to other pressure measuring devices. |
Limited Readability: Bourdon tube gauges can sometimes be harder to read than other pressure measuring devices due to their U-shaped tube bend. |
Conclusion
Bourdon tube gauges are a reliable and cost-effective instrument for measuring pressure in industrial applications. Their accurate pressure measurement through tube deformation offers high accuracy and reliability. Despite some disadvantages, Bourdon tube gauges can be used in many applications and provide a robust and durable solution for pressure measurement.
- Excellent load-cycle stability and shock resistance
- All stainless steel construction
- German Lloyd approva
- Scale ranges up to 0 … 1,600 bar
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- Safety version with solid baffle wall designed in compliance with the requirements and test conditions of EN 837-1
- Excellent load-cycle stability and shock resistance
- Completely from stainless steel
- Scale ranges from 0 … 0.6 to 0 … 1,600 bar
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Datasheet |
| User Manual |
| User Manual |
| User Manual |
| User Manual |
- Overpressure range is indicated completely on scale
- Safety version with solid baffle wall (Solidfront) designed in compliance with the requirements of EN 837-1 and ASME B40.100
- With case filling (model 233.36) for applications with high dynamic pressure loads and vibrations
- Measuring ranges from 0 … 0.6 bis 0 … 40 bar [0 ... 10 to 0 ...600 psi]
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Datasheet |
| User Manual |
| User Manual |
- Safety pressure gauge with solid baffle wall designed in compliance with the requirements and test conditions of the DIN 16001 high-pressure standard
- High load cycle stability, even with dynamic pressure profiles
- High indication accuracy of 1 %, optionally 0.6 %
- Scale ranges from 0 ... 2,000 bar to 0 … 6,000 bar
| Datasheet |
| User Manual |
- Safety pressure gauge with solid baffle wall designed in compliance with the requirements and test conditions of the DIN 16001 high-pressure standard
- Wetted parts from stainless steel 316L
- Long service life with static pressure profiles
- Scale ranges: 0 ... 2,000 bar, 0 ... 2,500 bar and 0 … 3,000 bar
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- Fully welded mounting ring to prevent water ingress into the control panel (ingress protection IP66)
- All stainless steel construction
- Optionally as safety version "S3" per EN 837-1
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Datasheet |
| User Manual |
| User Manual |
| User Manual |
- VCR® compatible face seal fittings
- Helium leak tested
- Electropolished case
- Process connection surface finish Ra ≤ 0.25 μm
| Datasheet |
- Excellent load-cycle stability and shock resistance
- Safety version with solid baffle wall designed in compliance with the requirements and test conditions of ASME B 40.100
- With case filling (model 233.34) for applications with high dynamic pressure loads and vibrations
- Scale ranges from 0 … 10 to 0 … 30,000 psi [0 ... 0.6 to 0 ... 2,000 bar]
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Datasheet |
| User Manual |
- Overpressure range is indicated completely on scale
- Safety version with solid baffle wall (Solidfront) designed in compliance with the requirements of EN 837-1 and ASME B40.100
- With case filling (model 233.36) for applications with high dynamic pressure loads and vibrations
- Measuring ranges from 0 … 0.6 bis 0 … 40 bar [0 ... 10 to 0 ...600 psi]
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Datasheet |
| User Manual |
| User Manual |
- POLARgauge® - special instrument design for extremely low ambient temperatures down to -70 °C [-94 °F]
- Ingress protection IP66 and IP67
- Completely from stainless steel
- Measuring ranges from 0 ... 0.6 to 0 ... 1,000 bar [0 ... 10 to 0 ... 15,000 psi]
- Case also available in safety level “S3” per EN 837-1
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Datasheet |
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User Manual
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- Safety pressure gauge with solid baffle wall designed in compliance with the requirements and test conditions of the DIN 16001 high-pressure standard
- Wetted parts from stainless steel 316L
- Long service life with static pressure profiles
- Scale ranges: 0 ... 2,000 bar, 0 ... 2,500 bar and 0 … 3,000 bar
| Datasheet |
| User Manual |