UDT Model 265 Photometric Sensor

The model 265 products consist of luminance sensors including an occluder ring for blocking ambient light. Ideal for measurement of displays, these sensors are designed with spectral responsivity that matches the human visual system, incorporating a silicon detector combined with a spectrally matched photometric filter.
The luminance head was specifically designed for measuring display brightness. Its integral lens provides a fixed field-of-view of 13 degrees and a soft rubber light shade eliminates errors due to ambient light and keeps the display from being scratched during measurement.
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.

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  • Field-of-view is 13 degrees
  • High accuracy photometric filter f1’ ≤ 3% standard, ≤ 1.5% special order
  • Luminance Measurements in nit (cd/m2) and foot-Lamberts (standard)
  • Luminous Intensity Measurements in candelas (special order)
  • Integrated fixed-focus lens for non-contact measurement
  • Standard 82.6 mm (P/N U23-01-184) or optional ‘mini’ 62.5 mm (P/N U23-01-184OPT) occluder

Key Specifications                                             Part No. U23-01-184 (OPT)

Field-of-View 13 degrees

CIE V (λ) Function

 f1’  ≤ 3% (standard)

 f1'  ≤ 1.5% (special order)

Detector Information

Silicon    0.34 cm2 active area

Dynamic Range

1 x 10-3 to 1 x 105 cd/m2

Typical Response

1.1 x 10-9 A/cd/m2 @ 555nm


ISO 17025, NIST Traceable


2 meter, included

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


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