Spectroradiometers
Spectroradiometers are high-precision light measuring devices that simultaneously measure the spectrum, luminance, chromaticity coordinates according to CIE, colour temperature and a variety of other photometric parameters. They are used in a wide range of applications, from display and lighting testing to research and development in the field of optical metrology.
Depending on the required measuring range and minimum luminance, the devices are equipped with either an uncooled or cooled photodiode array. The cooled versions enable particularly low-noise signal processing and ensure excellent contrast measurement, even at very low light intensities.
How it works
When measuring small character widths or tiny samples in a large field, a high-precision optical system is crucial to ensure exact alignment. Spectroradiometers with Pritchard optics are recognised as the most accurate and versatile solutions for such applications.
The Pritchard system combines reflex-based optics with a magnified field of view. The user sees the measurement object in high resolution through the eyepiece, with a black dot (the measurement aperture) marking the actual measurement field. Since only the light that passes through this aperture is detected, the measurement area is precisely defined and precise, repeatable measurement is possible.
The PR-655, PR-670, PR-7xx and PR-1050 spectroradiometers are particularly easy to use: after alignment and focussing, all you need to do is press a button to start the measurement. The system automatically adjusts the exposure time to achieve the best possible signal-to-noise ratio. A dark measurement to eliminate background noise is also carried out automatically so that reliable results are available in the shortest possible time.
In contrast to the PR-655, which only has a fixed aperture, the PR-670 offers four selectable apertures (1°, 1/2°, 1/4° and 1/8°). This means that both large and very small objects can be measured without the need for additional lenses or accessories. If the measuring spot is too large with the standard lens, the spectroradiometer can be equipped with special macro optics to achieve a measuring spot size of up to 0.0036 mm – ideal for the finest structures and high-precision contrast measurements.
In addition to measuring luminance and colour coordinates, these spectroradiometers can also be used to calibrate the white point of displays. It allows spectral-based adjustment using predefined or user-defined phosphor sets, which is particularly advantageous for display calibration in industry and research.
Thanks to the integrated colour touchscreen, a battery and the ability to save measurement data directly to an SD card, our spectroradiometers are not only precise, but also extremely flexible and mobile.
Spectroradiometers for OEM solutions
For OEM applications in which spectroradiometers are integrated into existing systems, we also offer a slimmed-down version of the PR-7xx series, the A-TAKT V-7HS. This version does not require a display or viewfinder, instead it has a USB targeting camera and a fixed focal length lens optimised for the application. This enables a compact, cost-effective solution for precise spectral measurement in automated or customised application.
What’s in this range?
All the variants in the range and a comparison of what they offer
| Model | PR-655 | PR-670 | PR-740 | PR-745 | PR-1050 |
|---|---|---|---|---|---|
Detector | Photo diode array 128 elements | Photo diode array 256 elements | Photo diode array (TE-cooled) 512 elements | Photo diode array (TE-cooled) 512 elements | Photodiode array (TE-cooled) 512Elements |
Wavelength | 380… 780nm | 380… 780nm | 380… 780nm | 380… 1080nm | 380… 780nm |
Minimum measurable luminance | 0,7 cd/m² | 0,03 cd/m² | 0,00002 cd/m² | 0,000001 cd/m² | 0,00002 cd/m² |
Maximum measurable luminance | 103.000 cd/m² | 8.566.000 cd/m² | 6.860 cd/m² | 3.430 cd/m² | 6.860.000 cd/m² |
Colour measurement accuracy | 0.0015 for CIE x,y | 0.0015 for CIE x,y | 0.0015 for CIE x,y | 0.0015 for CIE x,y | 0,0015 für CIE x,y |
Apertures | 1° or1/2° | 1°, 1/2°, 1/4° and 1/8°° | User defined | User defined | user-defined |
Minimal measuring spot with standard optics | 5mm | 0.7mm | 0.5mm | 0.5mm | 0.5mm |
Spectral resolution | 3.2nm | 1.6nm | 1nm | 2nm | 1nm |
FAQs
for Spectroradiometers
The Pritchard optics system enables precise measurement point determination through a central measurement aperture in the field of view. This ensures accurate alignment and precise measurements, even for very small light sources.
The devices measure luminance, spectral radiance, spectral irradiance, correlated color temperature (CCT), color rendering index (CRI), and color coordinates in various color spaces (CIE, Lab, Luv), among others.
The AutoSync® function automatically adjusts the exposure time to match the refresh rate of the display. This ensures that measurements are properly synchronized, which is particularly important for high-speed displays.
In addition to the standard optics, various magnification lenses can be used to achieve measurement spot sizes as small as 0.0036 mm
Yes, with the optional Bluetooth interface, the devices can be remotely controlled from up to 100 meters away. Additionally, PC software (SpectraWin® 2) is available for remote operation.
Yes, with the optional cosine receptor (CR), both illuminance and irradiance measurements can be conducted.
The cooled detectors reduce thermal noise, resulting in higher measurement accuracy and sensitivity—especially crucial for measurements at extremely low light levels.
The PR-655 and PR-670 spectroradiometers use SD cards for data storage. A 512 MB card can store over 80,000 measurements, and SD cards up to 1 GB are supported.
Yes, with the SpectraWin® 2 software, measurement tasks can be automated, spectral data analyzed, and custom calibrations performed.
Yes, with the RS-3 or SRS-3 reflectance standards, measurements of reflected radiation can be performed to determine reflectance levels and material properties.
The PR-655 and PR-670 spectroradiometers have fixed bandwidths of 5 or 8 nm. The PR-730 and PR-740 spectroradiometers offer a variable bandwidth option, allowing selection between 2, 4, or 8 nm depending on the required sensitivity or spectral accuracy.
Spectroradiometers from Photo Research can be purchased or ordered directly from Acal BFi. As the official European sales and service partner, we not only offer high-quality measuring instruments but also comprehensive services for your measurement solutions.
In addition to consulting and sales, we provide a calibration and repair service, carried out in our official European calibration laboratory of Photo Research in Gröbenzell near Munich. This ensures that your devices always operate with precision and reliability.
Whether for research, industry, or quality assurance – at Acal BFi, you receive precise and reliable spectroradiometers from Photo Research, backed by top-tier support and technical service.
