3.4 Additional equipment A lux metre may be equipped with a recording device for monitoring illuminance over time.
A lux metre may be equipped with a communication interface which enables additional devices to be connected.
3.5 Software With electronic lux metre, the device’s software used must be identifiable (except in cases which exclusively involve displaying the measured values without other functions). The software must be secured to prevent random or deliberate influence in the event of damage and must be in compliance with the technical standard document WELMEC 7.22).
3.6 Power supply Lux metres may be supplied from the mains using an adapter, or may be supplied from an independent source.
A lux metre with an external electricity supply must be able to connect to a power supply with a nominal value of 12 V or 24 V (alternating or direct current). Lux metres must be equipped with a suitable connector.
An independent power source must be defined in the manufacturer’s specifications, and the lux metre must indicate that it must be recharged from the power source or that the power source must be replaced, and must be blocked itself or shut off if the source voltage drops below the limit set by the manufacturer.
Battery-powered lux metres must be able to indicate the battery level.
3.7 Resistance to the effects of the outside environment 3.7.1 Mechanical resistance The lux metre’s design and materials used must ensure sufficient strength, stability and resistance to mechanical impact and free fall if the manufacturer declares such resistance in the device’s technical documentation.
3.7.2 Resistance to boundary conditions for storage and transportation The lux metre or components thereof must be resistant to the limit temperatures for storage declared by the manufacturer in the device’s technical documentation (declared degree of protection offered by the cover) without damage or impairment of its metrological properties.