The importance of biological reactors used in growing artificial tissue is rising. To monitor the metabolic state of living cells in the bioreactor, a non-disruptive measurement is required. Fluorescence-lifetime measurements provide the perfect tool for this analysis. Many applications already exist in order to determine the fluorescence-lifetime, but the majority of these require the addition of fluorescence-active substances to enable measurements. Every usage of such foreign material has an associated experimental risk to the cell. This paper investigates the use of auto-fluorescing substances and their changes in Saccharomyces cerevisiae (Baker's yeast) as a risk free alternative to fluorescence-active substance enabled measurements. The quantity of NAD(H), NADP(H) and certain amino acids are good markers for measuring the metabolic state of cells and can be identified by their fluorescence-lifetime and spectral properties. Fluorescence lifetimes can be determined from the decay of the measurement signals, which in turn characterizes the individual materials and their surrounding environment. Information about the quantity of the fluorescence-active substances can also be measured based on the received signal intensity. Here, we have shown there is a correlation between the fluorescence lifetime and the metabolic state of Saccharomyces cerevisiae.

Online process control systems often only detecting temperatures at a local area of the machining point and determining an integrated value. In order to determine the proper welding quality and the absence of defects, such as temperature induced stress cracks, it is necessary to do time and space resolved measurements before, during and after the production process. The system under development consists of a beam splitting unit which divides the electromagnetic radiation of the heated component on two different sensor types. For high temperatures, a sensor is used which is sensitive in the visible spectrum and has a dynamic range of 120dB.1Thus, very high intensity differences can be displayed and a direct analysis of the temperature profile of the weld spots is possible.2 A second sensor is operating in the wavelength range from 1 micron to 5 microns and allows the determination of temperatures from approximately 200°C.3 At the beginning of a welding process, the heat-up phase of the metal is critical to the resultant weld quality. If a defined temperature range exceeded too fast, the risk of cracking is significantly increased.4 During the welding process the thermal supervision of the central processing location is decisive for a high secure weld. In the border areas as well as in connection of the welding process especially cooling processes are crucial for the homogeneity of the results. In order to obtain sufficiently accurate resolution of the dynamic heating- and cooling-processes, the system can carry out up to 500 frames per second

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