Passive Ultra High Frequency Radio Identification (UHF RFID) systems used in metal objects exhibit challenges due to generation of Foucault currents and multiple reflections, creating reading problems and detection errors. One of these problems is unwanted RFID tag reads i.e., tags unintentionally detected by the reader. The paper presents one algorithm for reduction of such unwanted tag reads using normalized read rate and range of RFID tags. The algorithm was designed using extensive data from measurements of an actual RFID system with tags located over metal objects. Results show that the algorithm detects 96% of unwanted tag reads.