A sampling plan to test single phase in service watthour meters

Using the criteria outlined in the Code for Electricity Metering, Fifth Edition, a sampling plan to determine the in-service performance of self-contained single phase watthour meters and 3-wire network watthour meters rated 12kva and below is developed. The plan conforms to accented principles of statistical sampling and is based on the variables method. This plan has allowed a significant reduction in meter sample size to be realized with corresponding dollar savings. Application of the plan requires only that the combination of sample mean and sample standard deviation be compared with tabulated acceptable combinations of these two statistics.