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A new meter setup screen will appear. The meter setup settings are displayed in a scrolling area:
N.B. The meters in Approve must correlate with the Omni streams’s defined in Profile.
This will load the following data automatically from the flow computer:
Alternatively, enter these fields manually.
|Date Installed||This is the date on which the meter is being commissioned. It default to the date that the meter is added.|
|Base Curve Reference||This field will be used throughout Approve to reference the base curve – yyyy-mm-dd format is recommended for consistency.|
|Base Curve Type||Select MF or KF base curve.|
|Base Flow Rate||This base flow rate will be used to calculate a normalised meter factor on the Proved Historical Meter Factor chart.|
This will write the base curve data into the flow computer.
Test 1 passes if the current prove is within a given percentage deviation limit of the base curve.
If the meter’s proves do not align with the base curve (because the meter is using the wrong base curve) then you can assign an offset that will shift the base curve into the correct range. This is useful to help to get Test 1 to pass. Otherwise leave the Base curve offset as zero or blank.
Test 2 passes if the meter factor is within the tolerance limits of the control chart.
The meter factors are all normalised to the base flow rate.
The tolerance limits are defined using moving or fixed limits and are calculated using all previous passed proves from the current base curve including the data from the current untested prove.
The Control Chart Limits can set to use either “Moving” or “Fixed Limits”.
When Moving Limits are selected the tolerance limits are automatically calculated. The tolerance limits are based on a 99.5% confidence level of the student distribution table. Test 2 cannot be performed until there have been three successful proves.
If fixed limits are defined, the limit types and the limits need to be manually entered, along with the number of successful proves required for the test to start.
Test 3 passes if the meter factor is within a given percentage of the previous prove. It does not include aborted or struckthrough proves. Test 3 cannot be performed on the first prove. It is typically set as 0.1%. An investigation limit can be set up to raise alarm if required.
Other tests will not mark the prove as a pass or a fail, but will cause the prove to be flagged and brought to the attention of the measurement team in the daily prove status email.
Enter how often the prove must be performed into the ‘Maximum Days Between Proves’ field. A notification will be sent out to the measurement team if the meter has not been proved within this period.
Enter 20 into the maximum days between proves field.
The drift is the deviation limit from the 5th previous prove. A notification will be sent out if a prove exceeds this limit.
Enter 0.0025 into the ‘Drift’ Limit’ field.
Approve runs multi variable regression to predict the meter factor based on historical data for every prove. The variables that are included in the prediction can be defined for each meter. The default options are Flow Rate and Date. The regression can be viewed on the Meter Factor Regression chart and is currently for information purposes only.
Approve requires a given number of passed proves to have been recorded before the prediction can start. The higher the number of proves will increase the accuracy of the first predictions.
|Proves Required for Prediction||The minimum number of proves required for prediction.|
|Regression Limits||The regression limits define limits based on the predicted meter factor.|
|Prediction Variables||The variables that are included in the prediction can be defined for each meter. The default options are Flow Rate and Date. The regression can be viewed on the Meter Factor Regression chart and is currently for information purposes only.|
The meter will be added to the Meters list.