RODER · Inspection · Defects and non-destructive testing
Light, UV and illuminance
Lux meters and UV meters are instruments for measuring illuminance (lux) and UV/UVA/UVC irradiance, used in a wide range of industrial, construction, safety, health and research applications. Lux meters quantify the illuminance of lit surfaces, a parameter governed by the directives on the lighting of work environments (UNI EN 12464) for wellbeing and productivity. UV meters measure ultraviolet irradiance, essential for UV-C sterilisation applications (hospitals, food industry), for verifying UV curing lamps (printing, UV-curing coatings) and for safety in environments with UV exposure (industry, welding, sports facilities).
On this page
What the measurement is for: light, UV and illuminance ↑ up
UV applications are wide-ranging: UV-C sterilisation in hospitals, clinics and operating theaters (with verification of the germicidal dose actually applied); surface sterilisation in the food industry; drinking water treatment (with verification of the UV dose); UV curing of industrial coatings, inks and adhesives (with monitoring of UV-A lamp intensity); the printing industry (for UV-curing inks); monitoring of work environments with UV exposure (arc welding, industrial processes); Wood’s lamp inspections (fluorescence) for NDT penetrant testing, identification of traces at crime scenes and document verification.
Lux meters ↑ up
Lux meters use a silicon photodiode fitted with a V(λ) filter – a correction filter that approximates the response of the human eye under photopic conditions – to measure illuminance expressed in lux (1 lux = 1 lumen/m²). The typical range is 0.1 to 200,000 lux, with a resolution of 0.1 lux at low values and an accuracy of ±3-5% of the reading on professional models. The probe is generally separate from the readout unit and connected by a cable, to make measurement easier at precise working positions. Datalogger models record how illuminance varies over time, for analysing daylight levels in buildings (including the contribution of natural light).
Lighting standards ↑ up
The UNI EN 12464-1 standard (lighting of indoor work places) prescribes the minimum illuminance values for each type of activity: 100-300 lux for circulation areas and warehouses; 300-500 lux for general offices; 500-750 lux for precision work; 1000-2000 lux for very high precision work (watchmaking, microelectronics). UNI EN 12464-2 governs outdoor lighting. Illuminance checks are an integral part of workplace safety inspections (Italian Legislative Decree 81/2008) and of the commissioning of new lighting installations. Measurements are taken once the lamps have stabilised (at least 30 minutes after switch-on), with the sensor positioned at the height of the working plane.
UV meters ↑ up
UV meters use photodiodes with optical filters specific to each UV band: UVA (315-400 nm, the “black light” band used for fluorescence); UVB (280-315 nm, the sunburn band); UVC (100-280 nm, the germicidal band used for sterilisation). The sensors are calibrated in units of intensity (mW/cm² or W/m²) or of cumulative dose (mJ/cm² or J/m²) – the latter being essential for sterilisation applications, where the germicidal dose requires specific exposure times. Professional models come with interchangeable probes for the different UV bands, metrologically calibrated.
Reference standards ↑ up
The reference standards are: UNI EN 12464-1 and 12464-2 (lighting of work places); UNI 11142 (lighting measurements); ISO 8995 (lighting of indoor work places, international); IEC 62471 (photobiological safety of lamps); ICNIRP (UV radiation exposure limits for occupational safety). Periodic calibration of lux meters and UV meters is carried out with standard calibration sources certified to ISO 17025; the typical interval is annual.
Selection criteria ↑ up
The choice of lux meter or UV meter depends on the application: for illuminance checks in work places → a lux meter compliant with UNI EN 12464; for industrial UV curing → a dedicated UVA meter; for sterilisation → a UVC meter with dose measurement; for safety applications → instruments with configurable alarms. Range, accuracy, portability, data connectivity and ISO 17025 calibration are decisive criteria for the choice.
The information on this page is provided for information purposes. Although it has been compiled with the greatest care, it may contain transcription errors or typos: for precise, up-to-date information please contact RODER SRL directly.
Contacts & Information
Contact for general information : info@roder.it
Machine Vision Division of RODER : www.visiotronix.com
RODER Instruments Division : www.innovacheck.com
More about RODER : about us
The information contained in this website is provided for information purposes only. Although it has been prepared with the greatest care, it does not constitute a contractual offer or a binding commitment to supply. It may contain transcription, translation or typographical errors. For precise and up-to-date information, please contact our company directly.
Note: Some images on this website have been intentionally generated using artificial intelligence (AI). This is because, for many applications and projects, photographs of the actual installation or system cannot be disclosed owing to confidentiality agreements, contractual clauses and non-disclosure agreements (NDAs).