Firma:                   Waters

Modell:                474

Kommentar:        Dokumente engl.

The Waters 474 Scanning Fluorescence Detector is a high-performance unit that provides a high level of sensitivity for spectrofluorometric analysis.

Features

The Waters 474 Scanning Fluorescence Detector includes:

•     An optical design that maximizes sensitivity

•     Microprocessor control for greater versatility and reliability

•     An emission wavelength sweep function so you can obtain an emission spectrum

•     An excitation wavelength sweep function so you can obtain an excitation spectrum

•     An automatic second-order filter to enhance applications in the visible wavelength range

•     Optional optical filters that can be installed on the flow cell for specialized measurements

•     Quartz flow cell or cuvette cell, permitting measurement of ultraviolet fluorescence

•     Nine-stage photomultiplier tube for amplifying the emission radiation

•     Photodetector to compensate for excitation fluctuations throughout a scan

•     An RS-232 port to allow connectivity to the Millennium ³² data system

There are three critical optical design features in the 474 detector-.

•     A highly energy-efficient optics system that does not use lenses, minimizing reflection loss

•     An optics system that uses holographic concave diffraction gratings and aspherical mirrors to provide highly efficient monochromators in a Compact package

•     A 150 VV Xenon lamp that provides greater light energy for excitation

There are five critical microprocessor-based features:

•     Operating parameters that are set using the keypad

•     A multi-line liquid crystal display (LCD) that provides Information on the status of the 474 detector

•     Self-diagnostic messages that are displayed on the LCD

•     Digital processing that controls the entire signal processing system, assuring higher reliability and operational stability

•     An auto-zero feature that provides a wide range of Offset adjustment for the analog output

Operational Specifications

Monochromator                       Holographic concave diffraction grating (for both excitation and emission)

Light source                            150 W Xenon lamp

Wavelength range                              200 to 700 nm (for excitation and emission). Can be set from 0 to 900

Spectrum band width              Excitation: 18 nm

                                               Emission: 10, 18, or 40 nm (set an keypad)

Wavelength accuracy             ±2 nm

Wavelength repeatability         ±0.3 nm

Detector                                  Excitation-. Photodiode

                                               Emission-. Photomultiplier tube

Second order filter                   Automatically inserted into light path when Ex > 400 nm

Flow cell                                  16 µL (standard) or 5 µL

Maximum flow cell pressure   16 µL: 145 psi (10 bar)

                                               5 µL: 500 psi (34.5 bar)

Wetted surfaces                     Synthetic silica, fluororesin, PEEK, stainless steel
SXS-316

Sensitivity                                S/N for the Raman peak of water is 320 or above, where Ex λ = 350 nm and time constant is 1.5 sec, 16 µL cell (Instruments shipped prior to June 1997, S/N for the Raman peak of water is 200 or above)

Attenuation range (Recorder output) Ten steps, including 1, 2, 4, 8, 16, 32, 64, 128, 256, S

Gain range                               1, 10, 100, 1000

Response                                Fast, Standard, Slow, and digital filter

Signal processing                   Digital processing by A/D and D/A converters (with surrounding temperature compensation circuits)

Outputs                                   •     Recorder: 10 mV full-scale (can be inverted)

                                               •     Integrator: 1 V full-scale

                                               •     Marker output

                                               •     Leak output

Inputs                                       •     Marker input

                                               •     Auto Zero input

                                               •     Program reset

Program functions                  Time program with following variables:

                                               •     Wavelength change (excitation and emission)

                                               •     Gain

                                               •     Attenuation

                                               •     Wavelength scan

                                               •     Ex, Em Spectra

Wavelength scan functions    Manual and time program parameters:

                                               •     Time

                                               •     Interval

                                               •     Amplitude

                                               •     Memory location

                                               •     Ex, Em Spectra

Spectrum storage                   Ten locations for both emission and excitation spectra

Self-test diagnostics               •     Memory (ROM and RAM)

                                               •     DC power

                                               •     Excitation energy decrease

                                               •     Leak in cell

                                               •     Lamp use time

Lamp use timer                       Internat timer for accumulating the total hours an the
Xenon Iamp

Dimensions                            Width. 11.81 inches (300 mm)

                                               Height: 5.90 inches (150 mm)

                                               Depth: 18.11 inches (460 mm)

Weight                                     41.8 pounds (19 kg)

Power requirement                 115 VAC (90 to 132 V), 50/60 Hz

                                               230 VAC (187 to 264 V), 50/60 Hz

Power consumption                300 W maximum

Ambient temperature              10 °C to 32 °C (50 °F to 90 °F) operation

                                               10 °C to 60 °C (50 °F to 140 °F) storage

Relative humidity                     20 to 80%, non-condensing