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What is the tolerance used for evaluating Queries and Alerts? For example when using a query or an alert on pipes with calculated flow = 0, if the calculated flow is slightly different than zero (for example 0.000005 gpm), will the query or alert find this pipe?
Queries have no tolerance, while Alerts currently use a fixed tolerance of 0.001, applied to the respective storage unit (gpm for flow, psi for pressure, ft for level and HGL)
For example if a pipe has a flow of 0.000000000000001 gpm, the query on Flow = 0 will still not retrieve this pipe, whereas an Alert on Flow = 0 will. If the flow is 0.0005 gpm, the Alert will still trigger. However if the flow is 0.005 gpm, the Alert will not trigger.
Note:
1) This tolerance with Alerts is always evaluated on the flow in units of gallons per minute (gpm). So, if you’re using units such as L/s, this is internally converted to gpm first before checking the 0.001 tolerance.
2) Given the above, it is recommended that you use less than or greater than instead of equals for queries. For example if you’re looking to find pipes with zero flow, your query might be something like Flow < 0.01 gpm