A hot topic in the industry right now is in-situ calibration and the benefit of onsite calibration for thermal mass flow meters. While thermal flow meters have been touted as accurate instruments to measure gas flow, the instrument’s need for annual calibration is a significant inconvenience and expense. It often dissuades companies from choosing this gas measurement instrument.
What is calibration?
From a simplistic perspective, calibration is the process where a meter is checked for correctness. For a thermal mass flowmeter, the unit is reviewed or compared to a measurement taken at a specific rate or data point; then, compared to a known standard.
Like any measurement device, the gas mass flow meter needs to be calibrated from time to time to ensure the meter is accurate. Without using a calibrated instrument, there’s no confidence in the collected data. Why spend your company’s funds on a meter to measure gas flow if you’re not willing to assure the information is right? While this is a rhetorical question, I assure you that I have heard many people claim to waive a calibration because of the expense and inconvenience associated with it.
Why is calibration such a problem for thermal mass flow measurement? Imagine buying a meter to measure gas at a remote location. There’s the expense of hiring the contractor or employee to mobile to the inline unit. A year later, hiring another employee or contractor to return to the location, remove the meter and ship it back to the manufacturer (or some third-party lab). Then, of course, the expense of hiring someone a couple of months later to reinstall the now calibrated unit. Calibration, in this manner, is labor-intensive and costly.
What does in-situ calibration mean?
The Latin term in-situ means “in position.” In-situ calibration implies that a unit can be calibrated in position or on-site, removing the hassle and expense of returning the meter to the factory or lab for annual calibration.
Sage Metering has led the way for on-site calibration of flow meters and offers a real solution to the problem. With Sage’s new technology and In-Situ Calibration Check, it is possible to verify onsite that the instrument is calibrated and, therefore, accurate. Among the benefits of the In-Situ Calibration Check are saving time and money. Additionally, by performing frequent calibration checks, your company complies with the EPA GHG Reporting Rule and calibration requirements.
While Sage has pioneered this movement, there are a few thermal flow meter manufacturers now offering an in-situ calibration meter also. In the next couple of articles, I will discuss Sage Metering’s approach, along with other companies’ in-situ calibration efforts. Read the next article.
Sage In-Situ Verification Procedure
Learn more about the onsite calibration verification here.