台式分光度计(240-2150nm) | 瑆创光学电子商店

The fundamental measurement principle enables the measurement of both parameters, spectral absorption coefficient and spectral effective scattering coefficient. These two parameters are of interest for analyzing diffuse scattering samples based on their physical and chemical properties. Other laboratory measurement devices on the market perform the measurement and analysis based on the absorption or pure transmission only. This is not sufficient when an absolute measurement and more profound and deeper analysis of diffuse scattering samples is needed. Due to a specific algorithm in the software program, the absorption coefficient as well as the scattering coefficient can be determined. This is based on “radiative transport theory”. Further explanation can be found in these scientific publications, see following links: Absorption and Scattering of diffuse media: Theory  and Absorption and Scattering of diffuse media: Experiment.

Due to this unique measuring principle, it enables serving many different applications. Some examples follow:

              Effects of light propagation in a diffuse media

              Terms: 1) Illumination; 2) diffuse Reflection; 

              3) Reflection; 4) Refraction; 5) Absorption; 

              6) Scattering Angle; 7) diffuse Transmission; 

              8) collimated Transmission

Applications

    ● Material Analysis

    ● Biophotonics

    ● Active ingredient determinations

    ● Quality assurance

    ● Chemometrics

    ● Food analysis

    ● Pharmacy and cosmetics

    ● Physical parameter based rendering

See also our application related scientific publication about the Simultaneous Determination of Droplet Size, pH Value and Concentration to Evaluate the Aging Behavior of Metalworking Fluids.

Our our publication about the possiblity Improved Process Control by Using the Effective Scattering Coefficients to Determine the Fat Content in Homogenized Cow-Based Milk with Multivariate Data Modeling.

    Sample chamber: Several sample holders are available. 

    The large chamber space allows great freedom in sample      design.

               Measurement System with optional Laptop

Typical Spectrophotometer vs. SphereSpectro 150H

The challenge with the measurement of scattering media is that it cannot be comprehensively measured and analyzed with classic "spectrophotometers". This is because these typically only utilize the transmitted light and cannot differentiate between scattering and absorption. Spectrophotometers are an ideal measuring system for transparent / clear samples, but reach their limits with scattering samples. The measuring system described here is necessary for this kind of sample.

Whenever the measurement of absolute scattering and absorption coefficients is required, a typical spectrophotometer cannot fulfill the job. The SphereSpectro 150H is capable of measuring absolute values and therefore allows analysis of physical and chemical material properties based on the absolute measurement of absorption and scattering characteristics. For example, this kind of information is of interest for determining concentration levels or material properties in cross-linking processes. Another example is the determination of a sample’s appearance in rendering processes based on the absolute absorption and scattering values of the sample. This is typically of interest in dental applications or similar.

The sample preparation of the SphereSpectro 150H is much easier compared to conventional spectrophotometers. Solid translucent samples can be simply held with the sample holder. Liquid samples can be easily filled in the cuvettes that are available with the system. There is no need for any special physical or chemical pre-treatment of the sample to separate it into clear or transparent samples.

Scattering media

Scattering media are materials into which light can penetrate, but then spreads in different directions due to scattering centers at which it can change direction of propagation (scattering). These scattering centers are areas in the medium that have a different refractive index from the base medium (matrix) e.g. if there is a particle at this point. In scattering media, light can therefore again emerge from the side on which light was originally irradiated, the so-called diffuse reflectance. In addition, the light can be reflected at the boundary layer of the medium in the form of a (directional) reflection. Both effects together are called total reflection. In the case of samples whose expansion is small compared to the light propagation??, light can also escape on all lateral sides. Total transmission refers to the proportion of light that passes through a sample and consists of two components, collimated transmission and diffuse transmission. The collimated transmission is the proportion of the light that passes directly through the sample without any interaction, i.e. has not been scattered or absorbed. The diffuse transmission in turn is the proportion of light that is transmitted after interaction, i.e. after scattering within the medium.

    Example: Determination of the concentration of 

    ibuprofen and parcetamol suppositories using 

    linear superposition of the individual components

Software

Determination of the optical properties with an integrating sphere

Measuring the light emerging from a scattering sample with an integrating sphere and comparing the measured values with theory is one way of determining the optical properties of a scattering sample. The integrating sphere is required to measure the total refection and transmission of a sample layer. The sphere principally integrates the radiation over the entire sample surface. With the two measured quantities per wavelength, total reflection and total transmission, two unknowns of the sample per wavelength can be determined in principle. In the normal case, the two quantities spectral absorption coefficient and the spectral effective scattering coefficient are determined.

In order to make this method as precise as possible, a simulation of the light propagation within the integrating sphere is necessary, taking into account the whole setup including the sample. For this purpose, a powerful algorithm is provided in the software supplied with the system. After entering a few parameters (the most important are the thickness - for liquid samples, which are measured in cuvettes, this is the known thickness of the cuvette - and the refractive index of the sample) the fully automated evaluation starts. If one of these parameters is not known then there are various methods to determine them, including for instance, by a set of measurements on samples having different thicknesses. You are welcome to contact us for this purpose. Overall, it can be stated that measurement and evaluation take place within seconds to minutes. 

See our product video.

Product Brochure Link: 

  Laboratory measurement system for determining the spectral absorption coefficient and spectral effective 

  scattering coefficient of scattering media

  ● Simultaneous determination of scatter and absorption  (unique feature)

  ● Measurement on diffuse sample, solid or fluid (unique feature)

  ● Simple sample handling

  ● Measurement within seconds

  ● Table top device

  ● UV, VIS and IR spectral range possible

  ● Large sample compartment with several probe fixing options

  ● Precise and absolute measurements with low measurement uncertainty

  ● Minimal noise and stray light due to use of high end spectrometers

  ● Maximum light throughput based on imaging mirror optics

  ● Easy to change light source

  ● Plug & play with intuitive software package

  UV, VIS to IR (depends on version)

  Typical Applications

  ● Material analysis

  ● Concentration determinations

  ● Quality assurance

  ● Biophotonics

  ● Active ingredient determinations

  ● Chemometrics

  ● Food analysis

  ● Pharmacy, cosmetics

  ● Physical parameter based rendering

  ● etc.

  Calibratio

  by reference standard, wavelength calibration of spectrometers is included

  Spectral Detector

  Version 1: VIS (350 nm to 1050 nm)

  Version 2: VIS and IR (350 nm to 2150 nm)

  Version 3: UV, VIS and IR (240 nm to 2150 nm)

  Measurement Time

  Typical measurement time is within a few seconds.

  The measurement time of the high resolution mode is within 2 minutes.

  Typical Measurement Uncertainty

  Uncertainty Component

  Resulting Error in µs‘ 

  (Effective Scattering Coefficient)

  Resulting Error in µa

  (Absorption Coefficient)

  Refraction Index + 0.01

  Calibration

  For absolute calibration a reference standard is needed, see ordering information. All spectrometers are 

  wavelength calibrated.

  Miscellaneous

  Dimensions

  Temperature Range

  Storage: (-10 - 50) ° C

  Application: (10 - 30) ° C

  The device shall not be exposed to high humidity. Range 20% ~ 70% RH non-condensing.

  Power Supply

  AC (110 - 230) V

  (50 - 60) Hz

  42 kg

  Measurement Port Diameter

  25 m

  Software

  Software

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