Random Sample/In-Service Testing
The Random Sample module, sometimes referred to as the in-service testing module, is designed to manage the random and periodic testing of your installed meter population. Depending on the regulatory environment, utilities typically choose one of two methods to ensure the accuracy of the meter population.
These requirements may differ from regulatory agencies across the USA, so we will review your State’s PSC/PUC requirements to ensure the system can be configured to meet the regulations.
In periodic testing, every meter within a population is tested on a regular schedule. Historically, periodic testing was used for all meters, with varying intervals between tests depending on the meter type. Virtually all utilities have switched to random sample testing for domestic metering. However, interval testing is still common for high consumption accounts.
Random sample testing divides the entire meter population into groups. A group should consist of a homogeneous collection of meters that are considered to have an equal chance of failure. Typically meter groups are defined by manufacturer and model, although other factors can be used. Each year, a statistically significant sample is taken from each group and those meters are tested. The results from the sample are extrapolated to predict the accuracy of the entire group in the meter population. Some other complex mathematics are involved in determining the size of the sample and in the interpretation of the results, but with Meter Manager these calculations are done automatically.
TESCO Meter Manager Random Sample supports ANSI standards Z1.4 & Z1.9 (single, multi & double).