How to Calibrate a Pressure Gauge

Pressure gauges drift over time, providing less accurate readings that can jeopardize quality control and safety. For this reason, calibrating these instruments is essential to ensure they continue delivering accurate readings.

What Is Pressure Gauge Calibration?

Pressure gauge calibration entails assessing and optimizing measuring accuracy. A calibration technician tests the pressure gauge against a reference standard to determine its accuracy. If they find deviations, they adjust it if possible, up to standard, allowing your business to obtain accurate readings.

Frequent pressure gauge calibration is important for any company working with pressurized gas, liquids, vapors and solids. A trained and experienced technician can help you optimize this instrument while complying with regulatory standards.

Do Pressure Gauges Need to Be Calibrated?

Yes — routine calibration is paramount when your company relies on pressure gauges to evaluate equipment performance. Without reliable results, you risk sending out goods that fall short of customer expectations. Recalling and remaking those items can increase production costs and impact your brand’s reputation.

Bringing pressure gauges to spec can benefit your company by:

Maintaining quality control: An accurate pressure gauge confirms your equipment is producing high-quality products. By maintaining proper quality controls, your company can avoid the cost of substandard outputs.
Fostering safety: Calibrated pressure gauges empower your team to maintain optimal working conditions, protecting them from accidents.
Avoiding penalties: Optimizing pressure gauges allows your company to comply with FDA regulations and avoid penalties.
Promoting customer satisfaction: Accurate pressure gauges enable your company to observe quality control standards, satisfying customer expectations.
Protecting equipment: Calibration allows your team to maintain equipment at proper pressure levels and prevent damage.

What to Consider When Calibrating a Pressure Gauge

The calibration process considers various factors, including:

Accuracy classes: Pressure gauges have different accurate classes guiding the highest permissible error margin.
Height difference: To avoid errors, position the calibrator and gauge at the same height or account for the height difference.
Pressure media: The calibrator should use the same pressure media as the equipment the gauge connects to.
Adiabatic effect: When dealing with gas as the pressure media, allow the pressure to stabilize after rapidly changing it. Stabilization will minimize the adiabatic effect — a temperature change resulting from a fast pressure increase.
Calibration position: Test the gauge in the same mounting position as its actual application.
Leak testing: Before beginning calibration, test the gauge for leaks in the piping system.
Hysteresis: Consider the difference in readings when increasing or decreasing pressure to obtain accurate measurements.
Temperature and humidity conditions: Register the temperature and humidity changes during calibration because they can affect the accuracy of readings.

Pressure Gauge Calibration Procedure

Technicians use pressure calibration equipment to calibrate pressure gauges. Whether they use pneumatic, hydraulic, digital or dead weight testers, they must ensure these calibrators have accurate readings.

Here’s a step-by-step calibration process:

1. Preparing for the Calibration

Confirm the pressure gauge is free of contaminants and damage. Next, verify compatibility between the calibration equipment and gauge.

Exercising the gauge is another crucial step before calibration to minimize friction. Provide the gauge with maximum pressure, leave it for a moment, release the pressure and then wait another moment. Repeat the process three times.

2. Connecting the Calibration Equipment and Gauge

Connect the two items using the correct adapter or fitting accordingly.

3. Setting the Standard Pressure

Set a traceable standard pressure on the calibration equipment to test the pressure gauge’s accuracy. Register and compare the readings on both devices.

4. Repeating the Steps

Perform the same steps to confirm the gauge’s accuracy at every pressure point. If it passes the calibration, disconnect it from the calibrator.

How Often Should Pressure Gauges Be Calibrated?

Determining how often to calibrate a pressure gauge depends on environmental conditions, rate of use and manufacturer’s standards. Here are the different reasons for scheduling a calibration test:

Complying with manufacturer requirements: Observe the manufacturer’s pressure gauge calibration frequency to extend its life.
Preparing for a critical measurement project: If you have a major project coming up, send your gauges for calibration before using them on the job. Recalibrate them and compare the before-and-after results. Similar readings confirm that you can rely on your measurements.
Inspecting performance after impact: Sometimes, your pressure gauges may not show signs of damage after impact or overload. Still, internal components may not function correctly, skewing your measurements.
Complying with industry standards: Depending on your industry and operations, you may need calibrated, certified pressure gauges to take measurements.

Optimize Your Pressure Gauge With Garber Metrology

Garber Metrology is an expert in calibration. We are ISO 9001 Registered by NQA and ISO/IEC 17025 and ANSI/NCSL Z540-1-1994 Accredited by ANAB. We’ve carried out calibration tests for breweries, food processing plants, petrochemical plants, oil refineries and scientific applications in labs and the field.

Our technicians perform on-site or in-house calibration services with industry-leading turnaround times to minimize downtime. We’re also flexible, meaning we can pick up and drop off pressure gauges locally if an on-site visit isn’t possible. Our experience and commitment to meeting customer expectations enable us to deliver high-quality calibration services.