When dealing with the complex and involved workings of natural gas measurement, it’s a welcome relief to embrace simple and straightforward solutions when they exist.
With flexible adjustment options and designs for versatile measurements, Coriolis flowmeters succeed at simplifying procedures for selection, calibration, verification, and adjustment. Here’s just how Micro Motion achieves this:
Calibration Fluid Flexibility
The calibration fluid flexibility of Coriolis flowmeters allows a traceable liquid calibration to be used for traceable gas measurements, opening the door to allow meters to be placed directly into natural gas custody transfer measurement applications, without the necessity of a third party gas calibration.
Customers now have a choice to make depending on project priorities. Micro Motion ELITE meters have proven to be two times more accurate than the AGA 11 minimum requirements when calibrated at the factory on water. This gives customers the option to save time and expense by installing meters that come straight from the Micro Motion factory.
In contrast, when the absolute best accuracy and traceability directly to gas reference standards are the highest priority, Micro Motion ELITE meters can be adjusted using a new built-in multi-point piece-wise linearization feature. Some results in third-party laboratories are showing agreement as close as ±0.1% with gas reference standards.
Coriolis Meter Zeroing Best Practices
All Micro Motion flowmeter zeros are carefully calibrated at the factory, and for most applications it is ideal to use the factory-set zero. While in service, it is possible to easily check the meter zero to make sure it is accurate after installation and over time.
- To verify zero after installation:
- Temporarily block the flow path to ensure a no-flow condition
- Ensure the meter is full of fluid (gas or liquid, not both)
- Ensure process conditions are stable
- Initiate the Micro Motion Zero Verification tool
- Runs automatically to tell within a minute if meter zero is good
- Monitors 8 parameters to check stability of the process conditions and to check the current zero value setting
- Unstable process conditions are identified for the operator, if any exist
- If the zero value is good, the tool will recommend no adjustment
- As a precaution against capturing a bad zero value in the field, it is always possible to restore the original factory zero setting
Smart Meter Verification (SMV) and Secondary Verification
Diagnostic tools can provide greater certainty to confirm flow measurement accuracy in situ without a traceable flow reference standard.
- AGA Report 11 recognizes benefits of secondary verification
- Reduced lost and unaccounted for gas
- Better system balance
- Reduced prior-period adjustments
- Ability to perform more frequent checking at no cost
- Work practices may be updated to extend primary calibration intervals
- Records meter configuration parameters
- Assesses the health of meter
- Includes results of any secondary diagnostic checks
- Checks calibration easily; even easier than checking the zero with no interruption or process condition flow check required
- Improves safety, no seals broken or risk to additional people sent into the field
SMV is able to verify the calibration by analyzing the meter structure very much like a simple spring mass system. Sophisticated analysis of the meter signals can separate and isolate signals coming from the sensor that prove the health and constancy of the calibration from the signals that measure flow and density. This makes it possible to check the meter simultaneously with no interruption of the normal measurement functions of the meter.
It is rare for Micro Motion meters to suffer any damage that could cause a shift in calibration, but SMV will detect it if it ever happens.
Coriolis flowmeters by Micro Motion are simple and flexible to use in gas applications, reducing system losses and accelerating installation and start-up. Now more than ever, your company can be assured of safety and compliance with less effort due to the easy application and installation of these flowmeters.
