Specifying commercial atomic frequency standards using statistics

The use of statistics to set the specifications of commercial atomic frequency standards is considered. Different methods of doing this are indicated. Emphasis is placed on the use of statistics for normally-distributed data. Some of the pitfalls and problem areas are pointed out. Statistical data for Efratom´s Model LPRO rubidium frequency standard are used for illustration purposes. The benefits of standardizing the setting of specifications are discussed, and a proposal for some of the key items to be included in a possible standard is set forth