Illuminance and Colour Temperature Meter

What is the Illuminance and Colour Temperature Meter?

An illuminance and colour temperature meter measures both light level and the correlated colour temperature of a source. It is used for lighting installation checks and display calibration where white balance as well as brightness must be verified.

Overview

An illuminance and colour temperature meter pairs a photopic-filtered sensor with colour filters or a small multi-channel detector to estimate both illuminance and correlated colour temperature. The illuminance channel follows the photopic response, while the colour channels approximate the tristimulus values needed to locate the source on the Planckian locus. Some models also estimate colour rendering or dominant wavelength. Multi-channel designs are faster and cheaper than full spectral instruments but depend on calibration for common source types. They are widely used for on-site lighting commissioning, camera and display white balance checks and museum lighting assessment.

How does it work?

A lux meter converts incident light into a photocurrent with a silicon photodiode covered by a filter that approximates the CIE photopic response, which matches the sensitivity of the human eye. The signal is amplified and scaled to give illuminance in lux, equal to lumens per square meter. A diffuser and cosine corrector ensure the reading follows the cosine law of incidence and is independent of the angle of arriving light. Because the eye response peaks in the green region near 555 nm, the filter strongly attenuates ultraviolet and infrared radiation. Calibration against a reference lamp or standard photometer sets the absolute scale, and the meter is classified by accuracy and stability according to photometric standards. Temperature and stray light affect reading stability.

What are the key features?

• Combined illuminance and colour temperature measurement
• Multi-channel colour detection with illuminant selection
• Fast on-site readings for lighting commissioning
• Optional colour rendering or dominant wavelength output
• Hold, min-max and averaging functions

What are the technical specifications?

A typical illuminance and colour temperature meter configuration offers illuminance range of 0–200,000 lx, colour temperature range of 1,700–20,000 K, illuminance accuracy of ±3% of reading, colour temperature accuracy of ±2% of reading, sensor of Multi-channel photodiode with filters and cosine correction of Included. Values are indicative of the product class; the exact figures for each configuration are confirmed on the quotation and the calibration documents supplied with the instrument.

Which applications is it used for?

The Illuminance and Colour Temperature Meter is used in lighting installation commissioning, display and camera white balance checks, museum and retail lighting assessment and studio and stage lighting verification. Across the wider Lux Meters class, laboratories also deploy it for workplace and occupational lighting surveys, display and monitor brightness verification and greenhouse and plant growth lighting control.

Which standards and certifications apply?

Relevant standards and methods include ISO/CIE 19476, DIN 5032-7, CIE S 025, CIE 13.3 and IEC 61010-1. Certification candidates for this model are CE and ISO 9001 manufacturing; each is to be confirmed for the specific configuration before shipment, and certificates are supplied only where they have been issued.

Keep the photopic filter and diffuser clean and free of scratches, because contamination changes the response and biases readings. Zero the instrument in darkness where required, and verify periodically against a calibrated reference lamp or a meter of known accuracy. Avoid shading the sensor and measure at the working plane, holding the sensor in the same orientation as the surface of interest. Note ambient temperature and allow thermal equilibrium. Store meters with the sensor capped, and follow the calibration interval defined by the quality system, often annually.

How do I select the right Illuminance and Colour Temperature Meter?

Select this meter when both light level and colour temperature must be verified on site. Confirm the colour temperature range covers the sources in use and that the accuracy is adequate for the intended decision. Multi-channel meters are best for common white and daylight sources; for narrow-band or unusual spectra, a spectral instrument is more reliable.

How does it compare with other Lux Meters variants?

Choose a handheld lux meter for quick spot checks, surveys and field verification of lighting. Select a benchtop or logging model when measurements must be recorded, averaged or monitored over time. Match the measurement range to the space, since outdoor daylight can exceed 100,000 lux while corridors may be far below 100 lux. Confirm the cosine and colour correction, the stated accuracy class and the sensor calibration. For lighting design and colour work, a spectral illuminance meter adds colour temperature and colour rendering data. Check connectors or remote probes for hard-to-reach locations.