How to Calibrate a Pressure Transmitter at the Bench

How to Calibrate a Pressure Transmitter
How to Calibrate a Pressure Transmitter

Transmitters are widely used in industry to provide information about the performance of machinery. The readings of these devices allow technicians and machine operators to optimize their processes. Inconsistencies in measurements can have dangerous outcomes; therefore, organizations must strive for accurate data readings. That’s where transmitter calibration steps in.

Although transmitters are also used to measure the temperature, level, and flow of media, this post focuses on pressure transmitters.

Read on to learn how to calibrate pressure transmitter devices at your bench, and find the pressure transmitter calibration equipment suitable for your needs.

What Is a Pressure Transmitter?

Pressure transmitters are used with industrial machinery to measure the pressure, i.e., the expansive force of gases, liquids, and fluids. Also known as a pressure transducer, it is essentially a sensor made of a pressure-sensitive shell (steel, silicon, or other material) that measures the pressure inside a machine and converts this pressure to an electronic signal that can then be read on a display.

Pressure transmitters are used in a wide range of industrial sectors: the readings they provide alert plant operators before an incident occurs. However, over time, the performance of pressure transmitters decreases. If operators do not calibrate pressure transmitter instruments regularly, they can give inaccurate readings.

What Is the Importance of Transmitter Calibrations?

Calibration is the process of comparing a known value with the measurement result of the pressure transmitter; as such, it ensures that the readings of the measuring device are accurate.

The outcomes of inaccurate measurements of a pressure transmitter will vary, but in general, drift in readings can have a detrimental effect on productivity and process efficiency.

Additionally, it’s important to calibrate pressure transmitter devices to:

Maintain Safety:

Depending on the application, drift between the accurate and current readings can be dangerous and potentially life-threatening. Calibration helps maintain accuracy and thus provides greater safety, especially in process environments. Because calibrated products and components perform as expected, they are also safe to use.

Identify Errors:

Although high-quality transmitters are designed for long-term performance, reading errors can occur at any time. Transmitter performance may decrease due to operational stress or other factors in the operating environment. Periodical calibration helps identify these errors.

Avoid Damage:

Machine downtime is undesirable in industry as it leads to inactivity, wasted resources, and revenue loss. By regularly calibrating transmitters, plant operators can reduce or avoid machine downtime and maximize productivity.

Conform to Regulations:

Organizations must follow specific regulatory standards to be able to operate. Regulations often exist to ensure reliable, consistent quality to customers. Calibration is one step toward meeting such standards.

Why Do Technicians Calibrate at the Bench?

The main reason behind calibrating at the bench is that it allows for working effectively and accurately. Calibrating in the field using portable field equipment has its advantages and is useful for verifying performance, but this might come at the cost of less accuracy.

Calibrating at the bench, on the other hand, is carried out in a stable and clean environment, protected from factory conditions. The pressure transmitter calibration procedure at the bench helps prevent and assess component failure while providing the highest accuracy during the commissioning, testing, and calibration of transmitters.

Pressure Transmitter Calibration Equipment

You will need a few pieces of equipment to calibrate pressure transmitter devices at the bench successfully.

In principle, most pressure transmitter calibration equipment consists of:

  • The pressure transmitter you are about to calibrate
  • A calibrator used to simulate accurate pressure
  • A transmitter test hose
  • Test leads

How to Perform the Test

Calibration (e.g., calibration 4-20ma pressure transmitter) involves some necessary steps to get right, but it is a straightforward process overall.

Here is a step-by-step guide to calibrating the pressure transmitter at the bench:

Step 1: First, you need to find the transmitter test hose and connect it from the calibrator to the transmitter.

Step 2: After connecting the transmitter test hose, connect the mA measurement jacks of the calibrator to the transmitter.

Step 3: Verify that the transmitter test hose and measurement jacks are connected, then select the necessary function on the pressure/vacuum knob.

Step 4: Next, close the vent knob and supply the metering valve.

Step 5: Hold down the pump button to apply pressure/vacuum to the pump; release it once you need the necessary pressure.

Step 6: Correct the pressure by using fine pressure adjustment.

Step 7: Now, you can read and compare the reference value and the current pressure provided by the transmitter.

Step 8: The test is only complete if the measured mA signal at the test points is within tolerance. Adjust until within tolerance at all test points.


Pressure transmitters (devices that measure the pressure of gases and fluids) are used in a wide range of industrial sectors to verify the performance of machinery and to alert technicians before an event occurs. These devices must be calibrated regularly to ensure accurate readings and conform to regulations. Measurement inaccuracies can lead to inefficiency, decreased quality, and revenue loss, and they may even have life-threatening outcomes.

Technicians that calibrate pressure transmitter devices at the bench benefit from a stable environment that allows for accurate readings and helps identify faulty components. The pressure transmitter calibration procedure only takes a few steps, but regular calibration ensures the reliable performance of transmitters in the long run.

King Nutronics Corporation has over fifty years of experience in manufacturing test instruments and equipment. Continuous research and development in pressure and other specialized fields allow us to deliver products unmatched in accuracy, durability, and ease of use. King Nutronics pressure/vacuum calibrators allow for calibrating and testing absolute pressure/vacuum measurement devices, gauges, and switches. Our experienced engineers can design and manufacture pressure calibration equipment or adapt our existing solutions to meet your needs.

For more information on how to calibrate pressure transmitter devices, and choose the right pressure transmitter calibration equipment, contact us online or at (818) 887-5460 between 7 a.m. and 5 p.m. PST.

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