Instrument calibration is essential to ensure the accuracy of any thermal mass flow meter. The calibration establishes the relationship between heat transfer and the mass flow rate. During the manufacturing, the Sage flow meter is calibrated by placing the sensor in a NIST traceable calibration fixture. A known amount of gas flows past the sensor and the signal is measured. This is repeated multiple times over the specified operating range of the instrument. The data is then processed and loaded into the meter. Each thermal flow meter must be calibrated for the type of gas, mass flow rate, and pipe size. Further details on Sage Metering calibration facilities are available on the Calibration page.
There are occasions when the user wants to recalibrate or verify the calibration of the flow meter. This is especially desired when the flow meter is used for carbon credits and needs to meet various established protocols. Calibration verification is also required by the EPA to meet greenhouse gas emissions reporting requirements per EPA 40 CFR Part 90. For more information see Sage Metering’s white paper, Greenhouse Gas Emissions Monitoring Using Thermal Mass Flow Meters.
Historically a flow bench has been required to calibrate thermal mass flow meters. In these cases, the flowmeters are removed from service and returned to the manufacturer for recalibration, which is costly and time-consuming. Calibration, however, can be verified if it is possible to compare actual operating data with the original calibration data. This is made possible when a “no flow” condition is created.
With Sage Metering’s on-site calibration verification, it is possible to verify the meter is accurate in the field without removing it from service. Sage has developed a simple method to compare the signal of the thermal flow meter under a no-flow condition with the original calibration data. If the actual data matches the calibration data then the flow meter’s calibration has been verified. Furthermore, this test can be performed without having to remove the flow meter from the pipe or shut down the operation. The complete procedure is found in the instruction manual and also described in the In-Situ Calibration Check brochure.
This procedure has been accepted by leading carbon credit protocols and carbon credit management programs as a reliable and repeatable method to check the calibration of Sage flow meters Read more on Camco Carbon Credit Generation.
Award-Winning Flow Meter Calibration
The award-winning Sage Metering In-Situ Calibration Verification process is unique and outperforms other manufacturer’s calibration methods which may require removal of the instrument from the pipe or expensive additional hardware. The Sage process also verifies both the performance of the electronics as well as the sensor. More information can be found on Understanding the Sage Metering Calibration Verification. The in-situ calibration is available all the Sage meters, including the Sage Prime, Sage Clear, and Sage Rio.