Photometric Inline Monitoring of Pigment Concentration in Highly Filled Lacquers

The use of fiber‐optic backscattering sensors for inline monitoring of the particle concentration in highly filled dispersions and lacquer systems is shown. Through the miniaturization of the distance between transmitter and detection fiber to < 600 µm, the light can also permeate high disperse phase fractions of up to 60 %. Due to the measurement setup, both transmission and scattering effects can be found in the resulting signal. The possible mathematical description of the resulting nonlinear measured curve using a simplified model follows.BMBF, 03ET1471E, Mi2Pro: Skalierbare Milli- und Mikroproduktionstechnik zur energieeffizienten, kontinuierlichen Fertigung in der Prozessindustrie Teilvorhaben: Inline-Messtechnik für die Prozessüberwachung: Entwicklung und Validierun

A customized multispectral needle probe combined with a virtual photometric setup for in vivo detection of Lewis lung carcinoma in an animal model

Optical systems applied for tissue analysis are primarily based on single spectroscopic techniques. This paper however presents a multispectral backscattering sensor designed for in vivo application by a specially formed probe tip which allows side by side monitoring of ultraviolet, visible, near-infrared and fluorescence spectra. The practical applicability of the measurement system was demonstrated in vitro (muscle and adipose tissue) and in vivo in an animal model (mouse). By comparing associated measuring changes in biochemical, physical-morphological and colorimetric values this procedure allows a differentiation between healthy, marginal and malignant tissue

Marker-Free, Molecule Sensitive Mapping of Disturbed Falling Fluid Films Using Raman Imaging

Technical liquid flow films are the basic arrangement for gas fluid transitions of all kinds and are the basis of many chemical processes, such as columns, evaporators, dryers, and different other kinds of fluid/fluid separation units. This publication presents a new method for molecule sensitive, non-contact, and marker-free localized concentration mapping in vertical falling films. Using Raman spectroscopy, no label or marker is needed for the detection of the local composition in liquid mixtures. In the presented cases, the film mapping of sodium sulfate in water on a plain surface as well as an added artificial streaming disruptor with the shape of a small pyramid is scanned in three dimensions. The results show, as a prove of concept, a clear detectable spectroscopic difference between air, back plate, and sodium sulfate for every local point in all three dimensions. In conclusion, contactless Raman scanning on falling films for liquid mapping is realizable without any mechanical film interaction caused by the measuring probe. Surface gloss or optical reflections from a metallic back plate are suppressed by using only inelastic light scattering and the mathematical removal of background noise

Incremental Learning in Modelling Process Analysis Technology (PAT)—An Important Tool in the Measuring and Control Circuit on the Way to the Smart Factory

To meet the demands of the chemical and pharmaceutical process industry for a combination of high measurement accuracy, product selectivity, and low cost of ownership, the existing measurement and evaluation methods have to be further developed. This paper demonstrates the attempt to combine future Raman photometers with promising evaluation methods. As part of the investigations presented here, a new and easy-to-use evaluation method based on a self-learning algorithm is presented. This method can be applied to various measurement methods and is carried out here using an example of a Raman spectrometer system and an alcohol-water mixture as demonstration fluid. The spectra’s chosen bands can be later transformed to low priced and even more robust Raman photometers. The evaluation method gives more precise results than the evaluation through classical methods like one primarily used in the software package Unscrambler. This technique increases the accuracy of detection and proves the concept of Raman process monitoring for determining concentrations. In the example of alcohol/water, the computation time is less, and it can be applied to continuous column monitoring