Wavelength range, IR 7000 to 400 cm-1
Wavelength range, NIR determined by detector: 14000-5800 or 9000- 3850 cm-1
Resolution 1 cm-1 (0.5 cm-1 – option)
Interferometer Pendulum type with flat mirrors
Output beam diameter 38 mm
Optical axis height, interferometer 87 mm
Optical axis height, sample comp. 74.5 mm
Aperture ratio f 3.2
Beamsplitter, standard IR Multicoated KBr
Beamsplitter, option IR ZnSe
Beamsplitter, option NIR Fused Silica
Frequency reference VCSEL laser
IR source ceramic
NIR source Quartz-halogen lamp
Dessiccant possibility Yes
Interface USB
Data acquisition system 18 bit
Power 12 VDC, 30W
Dimensions, interferometer W35xD25xH16 cm
Dimensions, detector and

sample holding system

W37xD10xH12 cm
Weight 13 kg
Temp. environment 15 – 28 0C
Humidity environment Best below 65%


Interspec 403-X is an educational Fourier transform infrared/near-infrared (FTIR/FTNIR) modular spectrometer for teaching spectroscopy in the science and university labs to promote the use of infrared spectroscopy as a general-purpose, broad-based measurement tool, and to enable the use of state-of-the-art FTIR technology for teaching and science purposes.

With the wavenumber range from 7000 to 400 cm-1 (IR) / from 14000 to 3000 cm-1 (NIR) and spectral resolution up to 0.5 cm-1, the interferometer module with detector system forms an open architecture sample compartment modular spectrometer capable to use all FTIR accessories available in the market.

It makes the instrument very flexible for different kind of applications in science and teaching lab. The interferometer module has a transparent plastic cover to allow visual access to all of it’s major parts, 25-mm collimated output beam, a multicoated KBr beamsplitter, a high-intensity ceramic IR source, and an USB interface.

For easy access, those system components which have a finite lifetime (i.e. laser, and radiation source) are well accessible at the front side of the module. FTIR spectroscopic software Interspec for Windows is a program for running the spectrometer and for complete handling of measured infrared data.

Interferometer Performance

The interferometer compartment under cover is 170 x 190 mm wide and 90 mm high. The Interspec 403-X series of instruments employ a sealed and desiccated interferometer, ensuring high spectral integrity with low levels of water vapour within the interferometer.

We also offer a version (403-XZ) that employs a ZnSe moisture insensitive optics (beamsplitter and compensator) to be impervious to humidity. Near infrared version (403-XN) employs a fused silica optics and is insensitive to any influence of water vapour.

Resolution in the infrared is available up to 0.5 cm-1. The overall wavelength range is 7000 to 400cm-1 (IR) or 14000 to 3000 cm-1 (NIR).

Open architecture sample compartment

Open architecture sample compartment allows to use all ordinary FTIR accessories available in the market. IR or NIR detector unit with collimating off-axis parabolic and ellipsoidal mirrors plus sample slide mount is creating open architecture sample compartment.

In case of IR spectral region a selected high sensitivity DLATGS pyroelectric detector is available. In case of NIR spectral region two types of photodiodes are available: Si and InGaAs.  The InGaAs detector is with spectral range either from 0.7 to 1.7 µm or from 1.2 to 2.6 µm.


Open architecture sample compartment with detector system


Interspec for Windows is supplied on CD and provided with each system shipped. The software includes features for all standard analytical requirements including manipulation of spectral data, instrument control, plot with preview on the screen plus many others.

Also included are several facilities for analytical modelling of interferogrammes or spectra, with smoothing, and baseline correction, interactive editing and data manipulation.

Also spectral subtraction, mixture subtraction, smoothing derivatives, plot with preview etc. Data import and export is possible in ASCII, Excel, SPC or JCAMP formats.



Interspec 403-X – Standard FTIR Module with KBr optics.

Interspec 403-XZ – Non-hygroscopic FTIR Module with ZnSe optics

Interspec 403-XN – Near Infra FTIR Module with fused silica optics.

Interspec 403-X Data sheet – DOWNLOAD