Page 4 - Shimadzu UV-3600 Plus
P. 4

Highest Sensitivity in Class with

                     Three Detectors


                     The UV-3600i Plus provides precise transmittance or reflectance measurements in the ultraviolet to near-infrared     Comparison of Two Detector and Three Detector Models
                     regions. The level of sensitivity in the near-infrared region is significantly enhanced by using the combination of an   The UV-3600i Plus is newly equipped with an InGaAs detector in addition to the photomultiplier tube (PMT) and cooled PbS
                     InGaAs detector and a cooled PbS detector for this region. Spectra can be obtained without interruption for the    detectors.
                     entire range, with a high level of sensitivity and precision.                                                      That results in less noise than a two-detector (PMT and PbS detectors) model, especially in the region detected by the InGaAs
                                                                                                                                        detector (900 to 1600 nm).

                                                          InGaAs
                                                                                                                                                                         0.300


                                                                                                                                                                                                                  UV-3600i Plus
                                                                                                                                                                                                                  Two-Detector Model
                                                PbS                                                                                                                      0.200

                                                                                                                                                                         T%
                                                                                                                                        The figure on the right shows transmittance
                          PbS detector                                                         InGaAs detector                                                           0.100
                                                                                                                                        spectra (spectral bandwidth 2nm) for water
                                                                                                                                        measured with the UV-3600i Plus (InGaAs
                                                                                                                                        detector and cooled PbS detector) and a
                                                                   PMT                                                                  two-detector model (PbS detector) in the
                                                                                                                                        range of 1,370 to 1,600 nm. The noise level
                                                                                                                                                                         0.000
                                                       Optical system around detectors                                                  is significantly less with the UV-3600i Plus. (A
                                                                                                                                        mesh filter is used on the reference- beam
                                                                                                                                        side to maintain balance with the   -0.050
                                                                                                                                                                          1370.0  1400.0    1450.0      1500.0     1550.0     1600.0
                                                                                                                                        sample-beam side.)                                          nm
                                Sensitivity Characteristic
                       100
                                                                                                PMT detector
                                                                                                                                        High-Accuracy Measurement
                                                           PMT
                       Relative Value                      InGaAs    Conventional spectrophotometers use a PMT (photomultiplier tube)   Noise and bump caused by switching detectors is minimized to assure accurate measurement. Noise or bump is hardly observed
                                                                                                                                        even when using a transmission cell with a long optical path of 50 or 100 mm.
                                                           PbS
                                                                     for the ultraviolet and visible region and a PbS detector for the
                                                                     near-infrared region. Neither detector, however, is very sensitive
                                                                     near the wavelength of 900 nm, This prevents high-sensitivity        0.400                                          1.500
                                                                     measurements in this range. The UV-3600i Plus makes it possible to
                        0                                            take high-sensitivity measurements in the switchover range by        0.300
                                1000      2000      3000
                                                                     incorporating an InGaAs detector as shown in the figure on the                                                       1.00
                                    Wavelength (nm)
                                                                     left.
                                                                                                                                          Abs.  0.200                                    Abs.
                     Relationship between Detectors and Measurable Range                                                                                                                 0.500
                                                                                                                                          0.100
                          165 nm             380 nm                   780 nm                           3300 nm
                                                                                                                                          0.000                                          0.000
                                     UV                 Visible                          NIR                                                700.0       800.0       900.0       1000.0    1550.0      1600.0       1650.0     1700.0
                                                                                                                                                              nm                                             nm
                       PMT                    185~1000 nm                                                                                The figures above on the left and right are, respectively, transmittance spectra for ethylbenzene (obtained using a cell with an optical path of 100
                                                                                                                                         mm) and cyclohexane (obtained using a cell with an optical path of 10 mm). No baseline change is observed at the detector changeover
                      InGaAs                                             700~1800 nm                                                     wavelengths (870 and 1,650 nm).
                       PbS                                                                1600~3300 nm

                     Switching between the photomultiplier tube and the InGaAs detector is possible in the range of 700 to 1,000 nm (the default switchover
                     wavelength is 830 nm). Switching between the InGaAs detector and the PbS detector is possible in the range of 1,600 to 1,800 nm (the default
                     switchover wavelength is 1,650 nm).



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