The gas industry can be a maze of terminology, and the two terms often causing confusion are calibration and validation. In this blog, we will clear the air and explain the key differences between calibration and validation in a straightforward way.
Validation: Ensuring the System Does What It's intended
Validation is like a quality check for your gas equipment. It's all about making sure your systems are correctly set up, operating without hiccups, and delivering the results you expect. These standards can be set by external organizations or your internal quality guidelines.
Validation usually involves measuring a known standard to make sure the instrument is reading the correct number.
Calibration: Getting the Right Measurements
Calibration, on the other hand, focuses on making adjustments to the instrument to have it read the “correct” number. For example, for a pressure sensor, a known pressure is applied to the sensor and a measurement is made. Then the output of the sensor is adjusted so that it reads the pressure that was applied. So calibration involves applying a known standard and then adjusting the analyzer to eliminate the difference between the known and the measured values.
In the gas industry, calibration is vital when your equipment's sensors need fine-tuning. If your gas analyzers aren't giving precise data, calibration steps in to ensure they're back on track.
Why Calibration and Validation Matter in the Gas Industry
In the gas industry, both calibration and validation are of paramount importance:
Validation safeguards that your systems and equipment consistently deliver the expected results. It does not involve making adjustments as is the case in calibration. Regular validation is your safeguard against these potential problems.
Calibration guarantees that your measurement instruments are accurate. It's a foundational step in maintaining the precision of gas analyzers and other measurement devices. Accurate measurements are non-negotiable for safety and effective process control. Yet, it's worth noting that if your measurement devices drift for whatever reason, frequent calibration (2-6 times a year) is necessary. Sending them back to the factory for calibration could also be an option, but a costly and complex solution, involving shipping expenses, calibration fees, and extensive paperwork.
In a nutshell, validation is about checking if your system works correctly, while calibration is all about adjusting the output of a device to give you accurate measurements. Both play vital roles in the gas industry, helping maintain safety, quality, and compliance with standards and regulations. Recognizing their role is necessary to avoid confusion, and prevent regrettable damages and cost.
Why Some Analyzers Do Not Need Calibration
If the sensors involved in the measurement process are drift-free, and if they do not get fouled up by the fluid under measurement, then calibrations would not be necessary. This may sound simple, but it is actually a tall order.
Most analyzers have multiple elements that can drift. For example, aluminum oxide sensors for the measurement of moisture are notorious for drift problems.
If the analyzer uses fundamental first-principle measurements (please see the blog on first-principle measurements), then the chances of drift are minimized or eliminated.