The apparatus used for measuring the noise level must be a precision sound-level meter or equivalent measurement system meeting the requirements of class 1 instruments (inclusive of the recommended windscreen, if used).

Measuring instruments for cold water meters for non-clean water, alcohol meters, certain weights, tyre pressure gauges and equipment to measure the standard mass of grain or the size of ship tanks have been replaced, in practice, by more modern digital equipment.

Light Measurement Protocols: When light measurements, such as illuminance and luminance, need to be made, a LMD shall be used with the computer monitor located in dark room conditions. The LMD shall be used to make measurements at the centre of, and perpendicular to the computer monitor screen (Reference VESA FPDM Standard 2.0, Appendix A115). The screen surface area to be measured shall cover at least 500 pixels, unless this exceeds the equivalent of a rectangular area with sides of lengths equal to 10 % of the visible screen height and width (in which case this latter limit ...[+++]applies). However, in no case may the illuminated area be smaller than the area the LMD is measuring (Reference VESA FPDM Standard 2.0, Section 301-2H).

Measurements should be made at a point perpendicular to the centre of the screen using a Light Measuring Device (LMD) with the computer monitor in Off Mode/Standby Power (Reference VESA FPDM Standard 2.0, Section 301-2F).

An area measuring instrument serves for the determination of the area of irregular shaped objects, e.g. for leather.

Member States shall take appropriate measures to ensure that the operator informs the competent authorities within reasonable time limits about the results of the continuous measurements, the checking of the measuring equipment, the individual measurements and all other measurements carried out in order to assess compliance with this Directive.