Understand how anomalous conditions are detected

The Max Reasonable Flow Rate (vol/h) and Max Reasonable Reverse Flow Rate (vol/h) that you've entered on the Main tab of the Accumulator Row Edit dialog are used to detect anomalous conditions.

When an anomalous flow is observed that is outside of the boundaries of the Max Reasonable Flow Rate (vol/h) and/or the Max Reasonable Reverse Flow Rate (vol/h), this is identified by the system as being a anomalous delta.

In the event that there is an anomalous flow reported, the system waits for a defined time period which is configured in the Bad Delta Expiry Timeout (sec). If the system does not experience another bad delta during the waiting period, the bad delta counter will return to zero and no error message will be recorded. If the Maximum Bad Deltas are exceeded, an error message will be recorded.

The calculation that is used to determine whether the Max Reasonable Volume Delta has occurred can be calculated from the Flow Rate as follows:

The Reading Interval in this equation is the time between the current reading time and last accepted reading for the source rate point. The last accepted reading time is updated when one of the following conditions occur:

• When the accumulator experiences an input volume change. For example, if the current volume is 100 and the previous volume was 50, the accumulator will update the last accepted reading time.

• When the accumulator's Volume Update Timeout (sec) has expired. For example, if the Volume Update Timeout (sec) is set at 10 seconds, and the input volumes have not changed after 10 seconds, the accumulator will update the last accepted reading time.