High resolution satisfying European Pharmacopoeia (spectral bandpass: 1.5nm).
Trace-amount measurement in biotechnological field, etc. can be carried out using optional 50, 25
and 5mL micro-volume cells.

  • An abundance of optional accessories for various applications have been lined up.
  • Function for automatic data storage in a USB memory is incorporated.
  • Validation function and self-diagnostic function are standard with this instrument.
  • Measurement conditions can be saved.
  • The UV Solutions control program available at option enables the user to control operations from a personal computer.


  • 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 concave diffraction grating monochromator.

    Because a concave diffraction grating has both beam condensing and dispersing functions, an optical system can be 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 diffraction grating 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 1.5nm 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.


Optical system Double beam
Wavelength range 190 to 1,100nm
Spectral bandpass 1.5nm
Stray light 0.05% or less (220nm for NaI, 340nm for NaNO2)
Wavelength accuracy ±0.3nm (at 656.1, 486.0nm)
Wavelength setting repeatability ±0.1nm
Photometric range –3 to 3Abs
0 to 300%T
Photometric accuracy
(certified according to NIST SRM 930)
±0.002Abs (0 to 0.5 Abs)
±0.004Abs (0.5 to 1.0Abs)
±0.008Abs (1.0 to 2.0Abs)
Photometric repeatability
(certified according to NIST SRM 930)
±0.001Abs (0 to 0.5Abs)
±0.002Abs (0.5 to 1.0Abs)
±0.004Abs (1.0 to 2.0Abs)
Wavelength scan speed 10, 100, 200, 400, 800, 1,200, 2,400, 3,600nm/min
Response Fast, standard, slow
Baseline stability 0.0003Abs/h (at 500nm, 2 hours after power-on)
Noise level ±0.00015Abs (at 500nm)
Baseline flatness ±0.0006Abs (within 200 to 950nm)
Light source WI and D2 lamps
Light source changeover Auto (user selectable from 325 to 370nm)
Detector Silicon photodiode
Display U-2900: color LCD with backlight (26.4cm)
Printer I/F U-2900: Centronics interface
Serial I/F RS-232C (exclusive for UV Solutions program)
Size (main unit) U-2900: 500 (W) × 605 (D) × 283 (H)mm (with LCD lowered)
U-2910: 500 (W) × 605 (D) × 241 (H)mm (without PC and printer)
Weight (main unit) U-2900: 31kg, U-2910: 29kg
Power supply 100, 115, 220, 230 or 240 V, 50/60Hz
Power consumption 300VA

Software functions

  • Measurement mode
    Wavelength scan
    Time scan
  • Ratio (260/280)
  • Working curve type
    Polygonal line
    K factor input
  • Calculation of correlation coefficient
  • Concentration unit input
  • Kinetic assay
  • Spectrum and working curve printout
  • Spectrum display
  • Peak/valley detection
  • Tracing
  • Scale expansion/contraction
  • Smoothing
  • Differentiation
  • Area calculation
  • Fundamental arithmetic calculations between spectra
  • Data saving
  • Validation function
  • Automatic wavelength calibration
  • Lamp ignition time


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