The DA 7200 employs the most modern NIR technology – diode array technology, which has major advantages compared to older technologies such as scanning monochromators or Fourier Transform NIR (FT NIR).

No moving parts
Diode array technology is unique in the sense that it doesn't use any moving parts in the optics. This greatly improves the stability of the instrument as there are no parts that can be worn out or misaligned. The result is an instrument which requires much less maintenance than when moving parts are used, as for example is the case with scanning monochromators.
Click here for a simple picture of the optical principle of the DA 7200 (opens in new window).

1. A lamp illuminates the sample with white light. Some of the light is absorbed (depending on the composition of the sample) and the rest is reflected.
2. The light which is reflected hits a stationary grating, which separates the light by wavelength. Instead of white light, we now have a "rainbow".
3. Each wavelength is measured by a dedicated detector.

Extreme sensitivity
The detectors used are extremely sensitive. They can, and do, collect spectra 100 times per second. This makes it possible to analyze samples in ambient light, without using enclosures.

All wavelengths simultaneously
With diode array technology all wavelengths are measured simultaneously, as each wavelength has a dedicated detector. This is necessary in order to be able to analyze a moving sample as is done in the DA 7200 (the sample dish rotates during analysis in order to scan as large sample area as possible). Using scanning monochromator technology, the spectrum is collected one wavelength at the time, and if the sample moves the picture will be blurred.

Using diode array technology a full spectrum is collected of every part of the sample, whereas a scanning monochromator will collect one wavelength from one part of the sample and the next wavelength from a different part of the sample. This decreases the accuracy.