CHEMUSB4 Spectrophotometers

Our ultra-compact CHEMUSB4 spectrometer systems are ideal for routine absorbance assays using 1cm cuvettes. These fully integrated and preconfigured systems cover UV-VIS (210-880 nm) or VIS-NIR (370-985 nm) ranges. Each system includes spectrometer, light source and cuvette holder. The units interfaces to your PC via a USB cable. The VIS-NIR system is entirely powered by the USB.  The UV-VIS system uses a wall transformer to power the UV lamp.


Spectrometer and illuminated cuvette holder for 350-1000nm range.


Spectrophotometer 350-1000nm with light source, cuvette holder and complete spectra in 5 msec – Spectrecology


  • Plug and Play – easy to use fully calibrated integrated system
  • Comprehensive – system includes spectrometer, light source and cuvette holder
  • Smart Choice for Education – ideal for all kinds of experiments to learn about absorbance
  • Affordable!
Buy a CHEMUSB4-VIS Online!


Spectrometer and illuminated cuvette holder for200-850nm range.


UV-VIS array, USB coupled spectrophotometer, 200-850nm, complete spectra in 5 milli seconds – Spectrecology
  • Plug and Play – easy to use fully calibrated integrated system
  • Comprehensive – system includes spectrometer, miniature deuterium & tungsten light source and 1m cuvette holder
  • Excellent for analytical labs, affordable for Educators – ideal for all kinds of experiments to learn about absorbance
  • Illuminated cuvette holder can be removed for coupling the spectrometer to optical fibers


Physical Specifications CHEMUSB4-UV-VIS and CHEMUSB4-VIS-NIR
Spectrometer dimensions: 89.1 mm x 63.3 mm x 34.4 mm
Spectrometer weight: 190 g
Light source dimensions: 89.1 mm x 77.79 mm x 34.4 mm (UV-VIS)
40.7 mm x 88.8 mm x 34.1 mm (VIS-NIR)
Light source weight: 200 g (UV-VIS)
130 g (VIS-NIR)
Detector Specifications
Detector: Toshiba TCD1304AP Linear CCD array
Pixels: 3648 pixels
Pixel size: 8 µm x 200 µm
Pixel well depth: 100,000 electrons
Sensitivity: 130 photons/count at 400 nm; 60 photons/count at 600 nm
Optical Bench
Design: f/4, Asymmetrical crossed Czerny-Turner
Focal length: 42 mm input; 68 mm output
Entrance aperture: 25 µm wide slit
Wavelength range: 210-880 nm (UV-VIS)
370-985 nm (VIS-NIR)
Optical resolution: 1.0 nm FWHM
Signal-to-noise ratio: 300:1 (maximum signal)
A/D resolution: 16 bit
Dark noise: 50 RMS counts
Integration time: 3.8 ms to 10 seconds
Dynamic range: 3.4 x 106 (system); 1300:1 for a single acquisition
Stray light: <0.05% at 600 nm; 0.10% at 435 nm


Specifications for illuminated cuvette holders

Engineering Specifications USB-ISS-UV-VIS-2 USB-ISS-VIS
Dimensions: 198 mm x 105.1 mm x 40.6 mm 198 mm x 104.9 mm x 40.9 mm
Weight: 200 g 400 g
Wavelength range: ~200-1100 nm 390-900 nm
Cuvette pathlength: 1 cm 1 cm
Cuvette Z dimension: 15 mm 15 mm
Light source: Deuterium-tungsten Tungsten-violet LEDs
Bulb life (hours): 800 deuterium; 2,000 tungsten 2,000 tungsten; 45,000 LEDs


Buy CHEMUSB4-UV-VIS Online! Rent a CHEMUSB4-UV-VIS by the week!


The back story…

The very first USB based spectrometer was designed to replace our fiber optic S2000 and ISA plug-in A/D card system. The small compact size of the USB2000 suggested a new dimension for modularity, so we added a header pin on the front to allow direct connection of accessories. The very first was the VIS illuminated cuvette holder. This innovation eliminated a separate light source, cuvette holder and two fibers and shrunk the whole assembly to the size of a pack of cigarettes!

One hurdle was finding a way to fit collimation optics into a tiny package. A collimation lens was added to the spectrometer side, as the na of the spectrometer entrance port patched our existing lenses for fibers. On the illumination side we had a second problem. The power available from the USB 1.0 port precluded a very hot lamp, and we needed more energy in the blue end. So, we added a blue LED to the tungsten halogen lamp, making a hybrid light source. To blend the light in such a small space we used a diffuser.

Several years later, Heraeus (Germany) invented an RF excited miniature deuterium source. We were the first to make a commercial product from this new technology and worked to package it into the direct attach format for our USB2000 spectrometer. The engineering challenge was in providing the high voltage necessary to run the new lamp, and keeping the unit small. The result was our incredibly tiny UV-VIS spectrophotometer system.

These units have become the mainstay of CHEM-101 classes throughout the world, replacing thousands of old Spectronic 20 colorimeters. For many years we took Spectronic 20s as trade-ins and donated them for use in third world clinical labs (we still take trade-ins!)