UDT Instruments offers a wide range of photo-sensors for photometric applications. Basic sensors, used alone, are suitable for illuminance or irradiance measurements. Each type of sensor can be combined with various types of optical adaptors to form sensor head assemblies suitable for measurements of flux, intensity, luminance, or radiance.
UDTi photosensors and sensor heads are offered in three different mechanical configurations: Sensors from the Standard Series adapt for use with most accessories. The Miniature Series includes a similar range of sensors with a smaller-diameter package, compatible with UDTi’s line of integrating sphere accessories. The Low-Profile Series is designed for applications with limited mechanical clearance.
Model 211 Photometric Sensor Head
The model 211 is UDTi’s universal photometric head as it can be adapted for use with most accessories. It consists of a Standard Series silicon sensor a spectrally-matched photometric filter and a cosine diffuser to reduce directional sensitivity.
- Standard Calibration(s): lux; fc
- Photometric Filter Accuracy: < 1.0%
- CIE V(λ) Function: < f1' ≤ 3%
- Sensor Active Area (cm2): 1
- Dynamic Range: 1.0E-02 – 5.0E+05 lux
- Typical Response: 3.2E-09 A/lux @555 nm
- Features: High accuracy photometric filter (f’1 < 3%)
- Compatible Components: 2525; 2500; 1153; 1120; 116; 124; 114; 105; 106; 107
Model 263 Illuminance Sensor Head – Miniature
The Model 263 is a scaled-down version of the Model 211 designed for use in confined spaces. It consists of a silicon sensor with a spectrally-matched photometric filter and a cosine diffuser to reduce directional sensitivity.
- Standard Calibration(s): lux; fc
- Photometric Filter Accuracy: < 1.0%
- CIE V(λ) Function: < f1' ≤ 3%
- Sensor Active Area (cm2): 0.34
- Dynamic Range: 5.0E-01 – 5.0E+05 lux
- Typical Response: 7.3E-10 A/lux @555 nm
- Features: High accuracy photometric filter (f’1 < 3%)
- Compatible Components: 2575; With adaptor #1718: 2525; 2500
Model 268P Illuminance Sensor Head – Low Profile
- Standard Calibration(s): lux; fc
- Photometric Filter Accuracy: < 1.0%
- CIE V(λ) Function: < f1' ≤ 3%
- Sensor Active Area (cm2): 1
- Dynamic Range: 1.0E-03 – 2.0E+04 lux
- Features: High accuracy photometric filter (f’1 < 3%)
Model 424 LED Measurement Head
This sensor head couples a high-performance photopic sensor (based on the Model 211) with a special fixture to measure the averaged luminous intensity of LEDs according to the recommendations of CIE Publication 127 (illustrated above; LED Sockets sold separately). The intensity fixture precisely sets the distance and alignment between the LED and the sensor‚ so that measurement accuracy and repeatability are ensured. The system can easily be configured for either of the CIE-prescribed geometries: Condition A or Condition B. Measurement results are expressed in units of candela (cd). The sensor is calibrated over the visible spectral range‚ so that the nominal peak wavelength of the device under test can be selected during measurement‚ ensuring maximum possible measurement accuracy.
- Standard Calibration(s): Luminous Intensity (cd) for both CIE127 Conditions: A and B
- Dynamic Range: 1.0E-04 – 5.0E+04 cd
- UDT Instruments LED Sockets





