Microprocessor UV-VIS Double beam spectrophotometer LI-2904 with software




DOUBLE BEAM UV-VIS Spectrophotometer with more accuracy and flexible requirements. The two detectors are used measure sample and reference respectively and simultaneously for optimizing measurement accuracy. It has wide wavelength range satisfying requirement of various fields, such as biochemical research and industry, pharmaceuticals analysis and production, education, environment, protection, food industry etc.



   Optical System                               Double Beam (1200 Lines/nm Grating )

   Wavelength Range:                        190-1100nm

   Mode                                            Basic/Quantitative/Wavelength Scan/DNA Protein Test/Kinetics/Multiwavelength

   Scanning Speed                            Fast/Medium/Low

   Band Width                                   0.5/1.0/2.0/4.0 nm.

   Wavelength Accuracy:                   ±0.3nm

   Wavelength Repeatability:             0.2nm

   Photometric  Accuracy                  ± 0.3 % T

   Photometric Repeatability              0.2 % T

   Photometric Display Range            0-200% t, -0.3 -3.0A, 0 – 9999 C

   Stability                                       0.001 A/h @500 nm

   Baseline Flatness.                         ± 0.001A

   Noise                                          ± 0.001A

   Stray Light        :                         < 0.05%@220nm&360nm

   Data Output Port                          USB

   Printer Port                                 Parallel Port

   Display                                       Graphic LCD (  320×240 Dots )

   Lamps                                        Deuterium Lamp & Tungsten Halogen Lamp

   Detector                                     Silicon Photo diode

   Packing Dimension                      625×430×206 nm

   Weight                                       26 kg


?   Wide Wavelength range, satisfying requirements various fields.

?   Fully automated design, realizing the simplest measurement & satisfying the requirement of pharmacopeia

?   Maximum of 9 Wavelength & 8 Sample can be measured at one time

?   Automatic change –over Between W lamp & D2 lamp

?   Optimized optics and large scale integrated circuits design, light source and receiver

   From world famous measurement methods all add up to high performance and reliability.

  • Rich measurement methods: wavelength scan, time scan, multi wavelength Determination, multi –order derivative determination, double-wavelength method and triple-        wavelength methods etc, meet difference measurement requirement

?   Automatic 10 mm 8 –cell holder

?   Data Output can be obtained via a printer port and a USB interface

?   Parameters and data can be saved for user’s convenience.

?  Pc controller measurement can be achieved for more accurate and flexible requirement



Glass Cell                    :          4 nos.

Quartz cells                 :          2 nos.

Instruments Cover       :           1 no.

Software CD                :          1 no.

USB Cable                   :          1 no.

Operational Manual      :          1no.

Software Manual         :          1 no.

Software key              :          1no.



* Medicine/Pharmaceutical Industry

* Environment Monitoring

* Commodity Inspection

* Food Inspection

* Agricultural Chemistry

* Teaching in Colleges & Universities

* Metallurgy

* Geology

* Machine Manufacturing

* Petrochemical Industries

* Water and Waste water Labs

* Food and beverages Labs

Basic Mode

To measure the Absorbance and transmittance


  1. Coefficient Method
  2. Standard Curve Up to 10 Standard sample may be used to establish a curve. Four methods for fitting a curve through the calibration points :Linear fit. Linear fit through zero, Square fit and cubic fit.

DNA/Protein Test

Concentration and DNA purity are quickly and easily calculated: Absorbance

Rations : 260 nm / 280 nm with optional subtracted absorbance at 320 nm. DNA

Concentration = 62.9XA260-36.0XA280 Protein concentration = 1552xA260-

757.3xA 280

Wavelength Scan

  1. The wavelength scan intervals are 0.1,0.2,0.5,1,2,5 nm
  2. Hi, Medium and low scan speed are available. They vary from 100 to

3600 nm/min

  1. Wavelength are scanned from high to low so that the instrument waits

at high WL. And it minimizes the degradation of UV sensitive samples. 


This mode may be used for time course scanning or reaction rate calculations.

Abs v/s time graphs is displayed on the screen in real time, Wait time and measurement time up to 12 hours may be entered with time interval of 0.5,1,2,5,10,30 seconds and one min. Post-run manipulation includes re-scaling, curve tracking and selection of the part of the curve required for rate calculation. Rate is calculated using a linear regression algorithm before multiplying be the entered factor.


Download the specification document