Calculate volumetric change for linefill type devices

To calculate volumetric change for linefill type devices

1. Get current volume counter and related information from linefill device.

   Related information includes timestamp and data quality flags.

2. Check usability of the device volume. For more information on Device Volume, see Determine the usability of device volumes.
   

   If not usable, a zero volume delta is saved as the most recent delta and volume calculation for the device is done.

3. Determine delta volume (usability check has been passed).

   Delta volume is current volume minus previous volume.

4. Current volume is saved so that it can be used as the previous volume on the next processing.

5. Save the delta volume. The following occurs:

   • An array of past 30 minute volumes for the device is maintained.

   • Save the delta in the element for the most recent value.

6. Check the device as a source of imbalance.

   For more information, refer to Flag the input device as a leak location.