We developed the FSLTV Accu-Flow™ model refrigerant leak standard specifically for calibrating sniffer leak detectors. The FSLTV features a permeation leak element that eliminates the threat of clogging, a common problem with leak standards that rely on a capillary leak element. This problem is especially common for small leak rates of 0.1 oz/year or less. The FSLTV is available for a wide range of refrigerants, can be used with all makes of leak detectors, and can cover specified leak-rate ranges between 0.02 oz/year and 20 oz/year.