Wide measuring range

Yeasts are specially suitable, because they are able to use a wide substrate spectrum combined with a wide measuring range. 

A mechanical resistance is introduced into the flow and the resulting pressure drop is measured. Thus, flow measurement is transformed into the measurement of pressure difference. An orifice guage or standard orifice plate is generally used (Figure 2.8-5). Other types of throttle are the standard jet, the standard Venturi jet, and the spiral tube, which have the advantage over the standard orifice plate of a lower permanent pressure drop. This measurement principle is applicable over a wide measuring range, requires... 

This measurement principle requires the presence of liquids with a certain noinimum conductivity (at least 1 /iS cm for comparison singly distilled water has approx. 10 /fS cm ). The volume flow to be measured flows through a magnetic field perpendicular to the direction of flow (Figure 2.8-7). The induced electrical potential is recorded by two electrodes and used as measured quantity. The measurement is independent of the pressure and viscosity of the hquid, causes no additional pressure drop, and can be used over a wide measurement range (from several liters per hour up to 100 000 m h ). 

The AccuSizer 770 (by Particle Sidng Systons) is yet another new approach to providing a wide measuring range (0.S-2S00 pm), employing a combinaticHi... 

Comment they are very expensive but versatile. They deliver a signal and require no intervention on pipes. They have a wide measurement range. Used especially with corrosive fluids. 

The most common instrument using the above principle is the vernier caliper (see Fig. 6.6). Because of its capability of external, internal, step and depth measurements (Fig. 6.7), its ease of operation and wide measuring range, the vernier caliper is possibly the best general purpose measuring instrument. They are available in a range of measuring capacities from 0-150 mm to 0-1000 mm. 

Because of the generality of the symmetry principle that underlies the nonlinear optical spectroscopy of surfaces and interfaces, the approach has found application to a remarkably wide range of material systems. These include not only the conventional case of solid surfaces in ultrahigh vacuum, but also gas/solid, liquid/solid, gas/liquid and liquid/liquid interfaces. The infonnation attainable from the measurements ranges from adsorbate coverage and orientation to interface vibrational and electronic spectroscopy to surface dynamics on the femtosecond time scale. 

B2.4.2). The slope of the line gives AH, and the intercept at 1/J= 0 is related to A imimolecular reaction, such as many cases of exchange, might be expected to have a very small entropy change on gomg to the transition state. However, several systems have shown significant entropy contributions—entropy can make up more than 10% of the barrier. It is therefore important to measure the rates over as wide a range of temperatures as possible to obtain reliable thennodynamic data on the transition state. 

To solve a flow problem or characterize a given fluid, an instmment must be carefully selected. Many commercial viscometers are available with a variety of geometries for wide viscosity ranges and shear rates (10,21,49). Rarely is it necessary to constmct an instmment. However, in choosing a commercial viscometer a number of criteria must be considered. Of great importance is the nature of the material to be tested, its viscosity, its elasticity, the temperature dependence of its viscosity, and other variables. The degree of accuracy and precision required, and whether the measurements are for quaUty control or research, must be considered. The viscometer must be matched to the materials and processes of interest otherwise, the results may be misleading. 

Stress-relaxation measurements, where stress decay is measured as a function of time at a constant strain, have also been used extensively to predict the long-term behavior of styrene-based plastics (9,12). These tests have also been adapted to measurements in aggressive environments (13). Stress-relaxation measurements are further used to obtain modulus data over a wide temperature range (14). 

There are many techniques available for measuring the particle-size distribution of powders. The wide size range covered, from nanometers to millimeters, cannot be analyzed using a single measurement principle. Added to this are the usual constraints of capital costs versus running costs, speed of operation, degree of skill required, and, most important, the end-use requirement. 

The solubility of rhodamine 6G was measured in wide pH range. This model presumes predominating influenee of dimerie forms on the solubility. 

In Raman spectroscopy the intensity of scattered radiation depends not only on the polarizability and concentration of the analyte molecules, but also on the optical properties of the sample and the adjustment of the instrument. Absolute Raman intensities are not, therefore, inherently a very accurate measure of concentration. These intensities are, of course, useful for quantification under well-defined experimental conditions and for well characterized samples otherwise relative intensities should be used instead. Raman bands of the major component, the solvent, or another component of known concentration can be used as internal standards. For isotropic phases, intensity ratios of Raman bands of the analyte and the reference compound depend linearly on the concentration ratio over a wide concentration range and are, therefore, very well-suited for quantification. Changes of temperature and the refractive index of the sample can, however, influence Raman intensities, and the band positions can be shifted by different solvation at higher concentrations or... 

The measurement range of a thermistor is dependent on the probe type, typically -100 to +300 °C. The stability is not as good as that of metallic resistances. Thermistors are not standardized like some of the metallic probes. The thermistor has the advantage of a high change of the resistance with temperature. A very wide variety of sizes and shapes and a low price makes them attractive in relation to the metrological performance. 

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