Patent ID: 8448675

Claim:
For a fuel dispensing system for dispensing fuel from a dispensing nozzle into ORVR and non-ORVR equipped vehicles, the fuel dispensing system including a vapor recovery system, a method for monitoring for a restriction in the vapor recovery system comprising: for each fueling transaction, determining over a period of time an average of the A/L ratio for each fueling transaction either below a lower threshold or above an upper threshold, the upper threshold being greater than the lower threshold; determining whether a number of sequential fueling transactions having A/L ratios falling between the lower and upper thresholds exceed a threshold number; including fueling transactions having A/L ratios falling between the lower and upper thresholds in the average of the A/L ratios if the number of sequential fueling transactions having A/L ratios falling between the upper and lower thresholds exceed the threshold number, such inclusion to continue until a fueling transaction having an A/L ratio below the lower threshold or above the upper threshold is determined; comparing the determined average of the A/L ratios to a first lower test threshold and to a first upper test threshold; and providing an indication if the determined average of the A/L ratios is below the first lower test threshold or above the first upper test threshold.