The model 268P is a low-profile illuminance sensor designed for applications with limited mechanical clearance. These Photometric sensors are designed with spectral responsivity that matches the human visual system, incorporating a silicon detector combined with a spectrally matched photometric filter.  An integrated cosine filter significantly reduces directional sensitivity for ease of use.

Our wide range of optical power meters, photometric and radiometric sensors is complemented by ISO/IEC 17025 accreditation by NVLAP (NVLAP lab code 200823-0), resulting in unmatched performance and custom configuration as required.

  • Illuminance Measurements (lux)
  • Luminous Intensity Measurements (cd)    [at distance]

Key Specifications                                          Part No. U23-01-201

CIE V (λ) Function

 f1’  ≤ 3% (standard)

 f1′  ≤ 1% (special order)

Detector Information

Silicon   1 cm2 active area

Rise Time

3 µ sec

Dynamic Range(1)

1 x 10-3 to 2 x 104 lux

Typical Response(1)

8.536 x 10-9 A/lux


ISO 17025, NIST Traceable


1.5 meter, included

Compatible with the UDT Handheld and Benchtop series Optical Meters and Integrating Spheres.

(1) Stand alone with cosine receptor. Value may differ with cosine receptor removed.


UDT Model 268P Photometric Sensor