1.0 Mod-Spec UV/VIS

Figure 1.1: Optical overview of Mod-Spec spectrometer


Mod-Spec are line of UV-VIS spectrometers with a highly modular design, making them perfect as:

  • benchtop UV-VIS for variety of routine lab analyzes such as assays, kinetics experiments etc for research and education, environmental monitoring, life sciences etc

  • HPLC detectors (UV and fluorescence)

  • OEM applications such as integrating Mod-spec bench into a continuous pharmaceutical manufacturing process as part process analytical technology (PAT) for quality by design (QbD) paradigm (ICH. Q8(R2)


Mod-spec components such as the optical bench, the CCD control board, data acquisition software called ChemAnalysis Workbench are all completely open source, released under GNU General Public License (GPLv3), allowing for community driven development.


Advantages of Mod-spec:


  • Mod spec is completely modular, meaning that it its life cycle can be extended many times over a traditional instrument. Generally speaking, innovations in electronics and processor speeds have a far higher cycle of innovation than optics, which are virtually unchanged for last 20 years if not longer. An user can upgrade the electronics at fraction of new instrument cost by keeping the same optical bench.


  • We strive to ensure that replacement parts for Mode-spec components are available from major suppliers such as Thor Labs, Newport and Edmunds or used parts resellers such as BMI surplus. In any case, we make the CAD files (.dwg, .dxf) files available so our user can machine the parts if needed.


  • Detector control boards are powered by top of the line embedded processors by ARM. Our firmware is open source, and has been ported to boards powered by NXP and STM vendors, so there is no vendor lock-in and you'll never have to pay an arm and a leg to replace a burned out board.


  • Our open source data acquisition and analysis software, called ChemAnalysis Workbench, is built on java based eclipse platform for high level of modularity and functionality can be extended by very large number of plugins which can perform data analysis on R, python, visualization and document control, all meeting the regulatory cGMP requirements.


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2.0 Optical Bench


2.1 Overview

Fig 2.1: Exploded view of Mod-Spec optical bench


Part no.



Tungsten lamp


Lens mount


visible focus lens (biconvex, BK 7, ½'' diameter)


Deuterium lamp


Lens mount


Source lens (Plano-convex, UV fused silica, ½'' diameter)


Sample cell


Lens mount


Spectrograph lens (Plano-convex, UV fused silica, ½'' diameter)


Variable Slit (10 µm per micrometer division, range of 0-6mm)


adjustable height grating mount (0-33 mm)


concave reflective gratings


CCD detector


Table 2.1: Parts description