Technology

No moving parts

Diode array technology is unique in the sense that it doesn't use any moving parts in the spectrometer. 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.

  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.

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. Using scanning monochromator technology or Spinning filter wheel, the spectrum is collected one wavelength at the time, and if the sample moves the picture will be blurred.

Line Source Wavelength stabilisation

In all optical systems, microscopic mechanical movements occur over time and with temperature changes. These small movements give rise to changes in the wavelength scale and alignment. In order to achieve long term stability, it is imperative to correct for any such changes dynamically. In the DA 7300 On-line, this is done using a line source which brings the wavelength axis back to the starting point. The benefit with using a line source is that this emits light with peaks at certain wavelengths. The position of these peaks depend on the line source used and is constant with that material. This gives unsurpassed wavelength axis accuracy and long erm stability.

Dual lamp with automatic switch-over.

In order to avoid down-time and costly rush repair jobs, the system is fitted with dual lamps. Once the primary lamp reach the end of its working life, the second lamp is automatically put in to operation in a seamless transition.