U-2900/2910 Double Beam Spectrophotometer

Stable optics due to double beam

In double beam design, the energy of the light source is divided into two with a half mirror so that one passes through the reference side, and the other through the sample side, which is unavailable with the single beam design.

Since the reference-side energy is also incident on a detector, photometry is carried out on the basis of this signal. Therefore, an energy change in the light source can be compensated to ensure stable measurement for a long time.

Incorporation of stigmatic concave diffraction grating

The optics of this instrument adopts the Seya-Namioka monochromator widespread as a representative concavediffraction grating monochromator.
Because a concave diffraction grating has both beam condensing and dispersing functions, an optical system canbe configured with fewer mirrors.
In a spectrophotometer, use of fewer mirrors signifies a shorter optical path,thus giving rise to an aberration-free bright optics.

For elimination of the aberrations which were essentially unavoidable in the past, a stigmatic concave diffractiongrating has been developed by applying Hitachi’s original technology. As a result, a higher resolution has been realized.

A higher resolution has been achieved by eliminating coma from the Seya- Namioka monochromator which is the most popular concave diffraction grating monochromator. Its grooving is supported by the only ruling engine in Japan. The diffraction gratings of Model U-2900/2910 have also been made with this machine.

Spectral bandpass 1.5 nm satisfying European Pharmacopoeia

European Pharmacopoeia requires a ratio of 1.5 or larger when measuring 0.02% (V/V) solutions of toluene in hexane. In the spectrum at right, a satisfactory value of 1.6 can be confirmed.

Personal computer-based instrument control and data processing

U-2900 can be controlled by a PC equipped with optional UV Solutions Program. UV Solutions Program provides not only basic functions such as photometry quantitative analysis and wavelength scan but also the capability of data handling as described below.
(U-2910 is the model exclusively for operation with a PC. A PC equipped with Windows® is required for UV Solutions Program.)