Optical Testing Lab

Optical Testing

Among the capabilities of DTB’s optical testing laboratory is the measurement of Photometry and Radiometry of light and with light of a given object or source. Our optical testing lab has worked with a vast amount of products such as transparent armor, night vision goggles and laser visors.

Every object affects or interprets light differently, so appropriate and accurate measurements are needed to determine how much light is being produced by a source or cast upon an object. This can be measured with respect to power requirements and also how the human eye interprets that light.

Some of the optical photometric properties and optometric proportion we measure include haze and transmittance as well as optical distortion, deviation and densities. We also measure optometric properties of prismatic deviation and spherical and cylindrical powers.

DTB’s light analyzer is an integrated system designed to measure not only weighted and un-weighted photometric parameters such as total transmittance, but also haze with respect to both A and C illuminants. Our system is not limited to photometric measurements, but also can measure the radiometric power aspects of the item of interest as well.

To measure the illuminance/luminance and radiance/irradiance of an object our new optometer can be employed to take information from multiple photometric or radiometric detectors across the surface of an object.

DTB can test in accordance with many specifications such as, ASTMD1003 for transmittance and haze, ASTMF 2156 for optical distortion or any other requirements you may have such as ATPD 2352. Our optical testing lab has worked with a vast amount of products such as transparent armor, night vision goggles and laser visors.

  • Luminous Transmittance per: ASTM-D-1003, ATPD 2352 4.4.1, PMA202-07001, MIL-DTL-62420, ASTM F659, ANSI/SAE Z26.1, ASTM F1915
    • Photopic , Scotopic and Night Vision Goggle response functions
    • Standardized light sources A and C
  • Haze per: ASTM-D-1003, ATPD 2352 4.4.1 and PMA202-07001, ASTM F659, ANSI-SAE Z26.1
    • Taber Surface Abrasion testing for interior and exterior (threat surface) wear, per ATPD 2352 4.3.6, ANSI-SAE Z26.1 and ASTM D 1044
  • Optical Density per: PMA202-07001,MIL-DTL-62420, MIL STD 11352H
  • Optical Deviation per: ATPD 4.4.3, ASTM F801, MIL-DTL-62420
  • Optical Distortion per: ATPD 2352 4.4.4, ASTM D2156
  • Prismatic deviation per: PMA202-07001, ASTM F659
  • Spherical & Cylindrical Power per: PMA202-07001, ASTM F659, MIL-DTL-62420

The DTB testing lab is A2LA accredited and provides the latest in testing equipment and environments. Our experienced personnel can provide the level of professionalism required for reliable results.

  • Optical Testing
  • PASTM F801-96; ASTM F2156-06; ASTM D1003-00; ASTM D1044-08; ATPD 2352R Sections 4.4.1,, 4.4.2, 4.4.3, 4.4.4
  • Abrasion
    • ANSI/SAE Z26.1.1-1996, Sections 5.17 and 5.18; ATPD 2352R, Sections 3.3.6 and 4.3.6

Often there is a research need to characterize the photometric profile of light sources and to that end some useful photometric measurements that Dayton T. Brown, Inc., can provide to measure these light sources are explained in this outline.

Light sources can be characterized according to their wavelength spectrum as either narrow or broad-banded. For example, atomic resonance lamps such as sodium or mercury emit light only at certain wavelengths.

The spectral bandwidth of the light at each atomic line is generally very narrow. Lasers, of course, are effectively monochromatic (i.e. single wavelength). Conversely, arc lamps such as xenon, carbon arc and incandescent lamps emit over a very broad wavelength range with a few spectral features.

One useful measurement of light sources is Luminous Intensity or Candela (cd = lm/sr).

The candela is the foundation unit for the measurement of visible light. The candela is the luminous intensity, in a given direction of a source that emits light that has a wavelength of approximately 555 nm (yellowish-green) and that has a radiant intensity in that direction of 1/683 watt per steradian.

The candela value is independent of distance. One can think of it as the emission from the lamp without the interest in what happens to the photons it has ejected. The candela is frequently used when dealing with focused light for LEDs, flashlights or spots.