How to Test the Function of a Pressure Gauge

Pressure gauges are essential for measuring pressure fluctuations in fluid transmission lines, industrial supply systems, and fluid-operated equipment. Pressure is an integral part of industrial process control, making the accuracy and performance of these gauges critical to the safety and efficiency of these systems. Inaccurate readings can lead to sudden pressure buildup or pressure drop, severely damaging equipment.

Pressure Gauge

Testing pressure gauges before an application is essential for accurate readings and performance. While calibration and validation are necessary to ensure accuracy, testing is the most crucial part of the process. Two main types of tests need to be performed: functional testing and verification testing. Functional testing checks the device’s accuracy, while verification testing assesses if the device meets the manufacturer’s specified tolerance level. Both tests are mandatory and should be performed by manufacturers or users before and during the application. This post will discuss functional and verification testing processes for pressure gauges.

Pressure Gauge

Pressure gauges are essential for various industries – as they allow us to measure and detect pressure fluctuations. These gauges can come in either analog or digital displays and feature sensing elements like diaphragms, bourdon tubes, and springs.

Regardless of the type of gauge, testing it is of utmost importance.

Testing helps to ensure that the gauge is accurate and in working condition so that it can be relied upon to deliver results. Regularly testing your pressure gauges ensures their accuracy and reliability, saving you time and money in the long run.

Testing Pressure Gauges 

Testing pressure gauges for accuracy, performance parameters, and efficiency is essential for ensuring proper assembly, installation, and operation. Without regular testing, errors may lead to leakages, high-pressure buildup, sudden pressure drops, and even the potential risk of fluid lines bursting, which can cause serious injury or damage to operators.

test pressure gauge

To minimize these risks, pressure gauges need to be tested regularly. Two of the most common testing methods are verification and functional testing. Verification testing helps to determine the accuracy of a gauge’s readings. Functional testing evaluates the gauge’s performance against various parameters and performance standards. Depending on the results of these tests, activities such as calibration, maintenance, and troubleshooting can be performed.

What is Verification Testing?

Verification testing is an essential step in the calibration of gauges. By comparing the performance parameters of the indicator of working to those of the master gauge, we can ensure the gauge is operating at its highest possible accuracy and precision. This step is critical to ensuring accurate readings and consistent results.

Stainless steel pressure gauge


  • Master Gauge/ Calibrator
  • Disintegration Toolkit (For priming)
  • Valves (For Isolation of Gauge)


Step 1 Disconnect the gauge from the industrial system or isolate it using valves.

Step 2 If the system consists of any liquid fluid, release the air or gas trapped in the gauge or fluid transmission line. This may require priming the entire system.

Step 3 Connect the working gauge to the reference gauge, such as a calibrator or master gauge. Then, run the system and measure the readings on both gauges.

Step 4 Compare the readings from both gauges. If not, the error calculation should be done to move ahead with the calibration process.


The master gauge is the device of choice when it comes to the efficiency and accuracy of gauges. It is used as a reference for the calibration process, thus being known as a calibrator. Before measuring the pressure readings on the indicator of working and calibrator, it is vital to allow the system to settle for a while. This will help reduce fluctuations in the readings, ensuring greater accuracy and precision.

Shock-resistant Precision Pressure Gauge

What is Functional Testing?

Functional Testing is a necessary procedure to ensure that the operational capabilities of gauges are performing consistently and accurately. Through this test, any malfunction in the system can be identified and corrected before any more damage is caused.


  • Dead-weight testers
  • Test Gauge/ Reference Gauge


Conducting a functional test of pressure gauges requires the following steps:

Step 1 Cross-check the measuring range of the gauge from the manufacturer’s datasheets.

Step 2 Connect the gauge and reference gauge in the same pressurized industrial setup.

Step 3 Decide 5-point ranges such as 0%, 25%, 50%, 75%, and 100% on the measuring pressure range of the working equipment.

Step 4 Begin with 0% pressure and raise the pressure slowly up to 100%.

Step 5 Take readings on each point from both gauges.

Step 6 Compare the readings at all 5 points.

Step 7 Reverse the process and drop the pressure from 100% to 0%.

Step 8 Record readings during the reversed cycle.

Step 9 Compare the readings of pressure rising and dropping cycles.

Step 10 Compare the readings with the reference gauge’s readings to assess the accuracy of the gauge.

Testing and calibrating gauges and transmitters are essential for accurate measurement and operation. To ensure your equipment is functioning correctly, it is vital to source gauge testing and calibration services from experts like BCST. With years of expertise in the industry, BCST offers high-quality gauges and transmitters, along with reliable testing, maintenance, and calibration services. In addition, their team of experts is trained to handle any calibration job with precision and accuracy, helping you avoid costly errors. So take your time – get the best testing, maintenance, and calibration services from BCST.

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