General
Clamp-on meters are specified to achieve one to three per cent uncertainty. Manufacturers cannot control the quality of a given field installation and must provide latitude. Lab testing has demonstrated many installations perform at an accuracy level range of 1%. If a reliable installation technique is maintained, the clamp-on meter will often perform better than manufacturer standards. Further, the meter control units have piecewise linear error correction schemes such that they can be adjusted to reference flow rates as afforded at a flow lab.