3.8 Electromagnetic compatibility Lux metres which contain electronic components may not be influenced by electrical or electromagnetic interference, or must react to such interference by defined means (such as by announcing an error, blocking measurement and similar). In addition, they may not radiate an undesired electromagnetic field.
The electromagnetic environment class E1 is defined for lux metres containing electronic components (i.e. residential or commercial environment or light industry operating environment).
3.9 Resistance to unauthorised tampering Lux metres may not have properties which would facilitate fraudulent use, and the possibility of unintentional misuse must be minimal. Components which the user is not allowed to disassemble or adjust must be secured to prevent such activity.
The lux metre’s adjustment elements must be secured so that the settings cannot be changed during normal use without damaging the official seals.
4 Measuring instrument markings
4.1 General
All writing and symbols must be easily visible, legible and indelible under normal conditions.
Lux metres must be marked with at least the following information:
the manufacturer’s name,
type designation,
the serial number of the measuring instrument and sensor (if detachable),
4.2 Marking with official marks It is necessary to ensure sufficient room for placing the type approval mark and official mark(s) fulfilling the following requirements:
placed at a location where the label cannot be damaged during normal use of the device.
If the lux metre is equipped with an aperture for accessing the calibration elements, it must be sealed by a small stamp. Likewise, there must be at least one screw in the cover of the device which, when removed, enables access to the calibration elements.
