Sch 1B Pt 1 para 4 Instrument checks
At the choice of the manufacturer, either an accredited in-house body or an approved body, chosen by the manufacturer, shall carry out instrument checks or have them carried out at random intervals determined by the body, in order to verify the quality of the internal checks of the instrument, taking into account, inter alia, the technological complexity of the instruments and the quantity of production. An adequate sample of the final regulated measuring instruments, taken on site by the body before the placing on the market, shall be examined and appropriate tests as identified by the relevant parts of the designated standard, and/or normative document, and/or equivalent tests set out in other relevant technical specifications, shall be carried out to verify the conformity of the instruments with the relevant requirements of these Regulations. In the absence of a relevant designated standard or normative document, the accredited in-house body or approved body concerned shall decide on the appropriate tests to be carried out. In those cases where a relevant number of instruments in the sample do not conform to an acceptable quality level, the accredited in-house body or approved body shall take appropriate measures. Where the tests are carried out by an approved body, the manufacturer shall, under the responsibility of the approved body, affix the approved body's identification number during the manufacturing process.