Calculate volumetric change for Tank type devices

To calculate volumetric change for Tank type devices

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

   Related information includes timestamp and data quality flags.

2. Check usability of the device volume.

   For more information, 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 (filtered).

   1. Calculate the raw delta volume. This is current volume minus previous volume.

   2. Calculate the filtered delta volume from current and previous raw delta volumes.

      For more information, see Understand tank filtering.

4. An alarm is raised if delta volume is negative or if delta volume exceeds 10% of the rollover value. If delta volume is negative, a zero delta volume will be used.

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

6. Save the delta volume. An array of the past 30 minutes of volume reading is maintained for each device.

7. Check the device as a source of imbalance.

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