Showing papers on "Calibration curve published in 1984"
TL;DR: In this paper, a nonlinear calibration curve for volume fraction vs integrated intensity ratio was obtained for the monoclinic-tetragonal ZrO2 system by using X-ray powder pattern-fitting and pattern-decomposition techniques.
Abstract: A nonlinear calibration curve for volume fraction vs integrated intensity ratio was obtained for the monoclinic-tetragonal ZrO2 system by using X-ray powder pattern-fitting and pattern-decomposition techniques. The empirical equation agrees well with the theoretical one. By using this equation, the deviation from linearity (6.8% maximum) resulting from the intensity difference of corresponding reflections of the two phases can be estimated quite accurately.
835 citations
TL;DR: In this article, the size-exclusion chromatography (SEC) calibration curves are calculated using a range of models starting from those with simple, uniform pore geometry and culminating in a computer-assembled model, consisting of random-size touching spheres.
108 citations
TL;DR: In this paper, the authors present a variance analysis for quantifying the different sources of errors induced on volumetric water content measurements and calculation of soil water storage with the use of a neutron moisture meter in one single access tube.
Abstract: We present a variance analysis for quantifying the different sources of errors induced on volumetric water content measurements and calculation of soil water storage with the use of a neutron moisture meter in one single access tube. For comparative purposes, we apply the analysis to field data obtained with two different probes. In each case the calibration curve is established by measuring simultaneously and independently neutron count rates and corresponding water contents. Two different approaches are considered, i.e. the unbiased treatment and the biased treatment. The unbiased treatment differs from the biased by its correction for measurement errors using the leastsquare technique. For the site under consideration, we show that the calibration component is the major contribution to the total variance associated with an individual water content estimation. The use of the unbiased statistical treatment notably decreases the total variance. In cases where the calibration curve is established very accurately, the instrument component can be reduced by increasing the number of count replications at each sampling point or the counting time or both. The loss of precision due to using neutron count rate ratios instead of simple count rates is negligible if several count replications are made in a standard medium or if the counting time is long enough. We show that the rule of integration of water content profiles in order to calculate water storage has a great importance: the use of Simpson's rule drastically decreases the associated variance as compared with the classical trapezoidal method.
102 citations
Patent•
19 Sep 1984TL;DR: In this paper, a multicomponent quantitative analytical method and apparatus is described, wherein the method includes the steps of and the apparatus is capable of performing steps of obtaining a plurality of calibration spectra, transforming the calibrated spectra using a transform with orthogonal basis vectors, obtaining a calibration matrix relating the transform spectra to concentrations of analytes in the calibration samples, and relating the transformed unknown sample spectrum to the calibration matrix to determine the concentration of analyte in the unknown sample.
Abstract: A multicomponent quantitative analytical method and apparatus wherein the method includes the steps of and the apparatus is capable of performing steps of obtaining a plurality of calibration spectra, transforming the calibration spectra using a transform with orthogonal basis vectors, obtaining a calibration matrix relating the transform spectra to concentrations of analytes in the calibration samples, obtaining a spectrum for an unknown sample, transforming the unknown sample spectrum, and relating the transformed unknown sample spectrum to the calibration matrix to thereby determine the concentration of analytes in the unknown sample.
75 citations
TL;DR: In this article, a medium-voltage spark was used for the direct nebulization of compact metallic samples and non-conducting powders and the elutriated material was excited in a high-power argon/nitrogen inductively coupled plasma (ICP).
65 citations
Patent•
24 Dec 1984TL;DR: In this article, a method of calibrating a flow cytometer is based on a set of highly uniform microbeads associated with a fluorescent dye in such a way that the micro beads have the same excitation and emission spectral properties as the samples which are to be measured.
Abstract: A method of calibrating a flow cytometer is based on a set of highly uniform microbeads associated with a fluorescent dye in such a way that the microbeads have the same excitation and emission spectral properties as the samples which are to be measured. The calibration values of the microbeads are plotted against the relative fluorescence intensity peak channel for each microbead in the set. From this calibration plot, the relative fluorescence intensity peak channel of the sample is translated into equivalent soluble fluorescent dye molecules per sample particle. The calibration values of the standard microbeads are determined against solutions of the dyes. In cases where the background scatter of the bulk microbeads suspensions is too high for a direct determination against the solutions, a different set of microbeads with low background scatter is calibrated against the dye solutions and used to make an initial calibration of the flow cytometer, which in turn, is used to calibrate the uniform microbead standards. A novel method of making the microbead standards is also disclosed.
58 citations
TL;DR: In this article, the suitability of a Kalman filter for processing slowly varying parameters of a linear calibration graph is described, and the recursive algorithm predicts the changing parameters in time, which are used for the evaluation of unknown samples.
54 citations
TL;DR: In this paper, a palladium MOS field effect capacitance with a thin layer (3 nm) of iridium surrounding the palladium gate is used to detect ammonia in aqueous solutions.
48 citations
Patent•
12 Sep 1984
TL;DR: In this paper, the calibration curve corresponding to each test paper is stored in each of component amount data memory means 6a, 6b, 6c, respectively contained in test papers A, B, C with respect to reflectivities in a reflectivity range of 100%-0% and the amounts of components to be inspected are stored therein as data.
Abstract: PURPOSE:To obtain a biochemmical measuring apparatus capable of performing measurement with respect to a different kind of plural test papers even by one measuring apparatus, by changing over and selecting a calibration curve built in corresponding to each test paper. CONSTITUTION:The optical system 4 of a biochemical measuring apparatus consists of a test paper mount part 1, a light emitter 2 and a light receiving part 3 and the calibration curve corresponding to each test paper is stored in each of component amount data memory means 6a, 6b, 6c. Calibration curves are respectively contained in test papers A, B, C with respect to reflectivities in a reflectivity range of 100%-0% and the amounts of components to be inspected are stored therein as data. For example, when the component amount data memory means 6a corresponding to the test paper used in a selection/ setting means 7 is selected and set, the light receiving ratio of a specimen to be measured is calculated on the basis of the quantity of light outputted from the light receiving part 3 by a light receiving ratio operation means 5. By this method, corresponding component amount data is outputted from the selected component amount data memory means 6a and measurement matched with desired test paper can be performed.
40 citations
TL;DR: Several curve fitting methods, including linear, quadratic, and rational least squares fits and linear, cubic spline, and Stineman interpolations, are evaluated for their ability to fit highly nonlinear atomic absorption analytical calibration curves as discussed by the authors.
37 citations
TL;DR: In this paper, a relative efficiency calibration curve for a 2.2 m McPherson grazing incidence monochromator has been established using cascade relations in Be-like heavy ions.
Abstract: Previously a relative efficiency calibration curve for a 2.2 m McPherson grazing incidence monochromator has been established using cascade relations in Be-like heavy ions. The curve has now been confirmed and extended to cover the wavelength range 10 nm ≤ λ ≤ 80 nm using branching ratios for Δn ≠ 0 transition in Li-like ions. A summary of various measurements applicable to problems of astrophysical and plasma physics interest is given.
01 Aug 1984
TL;DR: In this paper, an apparatus for calibrating local heat flux gages in convective air flows is described, where heat transfer from a hot gage to a cold fluid is measured using a guarded hot-plate technique.
Abstract: An apparatus for calibrating local heat flux gages in convective air flows is described. Heat transfer from a ''hot'' gage to a ''cold'' fluid was measured using a guarded hot-plate technique. The system was used to calibrate Gardon-type circular foil heat flux gates of 1/8 in. and 1/16 in. outer diameters. The reslts indicate that the calibration curves are nonlinear, which is different from the linear calibration obtained using the standard radiation technique. The degree of nonlinearity matches the analysis which accounts for the effect of the temperature distribution in the gage foil. The effect of this temperature distribution can be neglected in the standard radiation calibration but is often significant in convection applications. These results emphasize the importance of calibrating heat flux gates in thermal environments similar to those in which they will be used.
TL;DR: In this article, Gel Permeation Chromatography of Polysaccharides: Universal Calibration Curve is used to measure polysaccharide properties and the convergence curve of the curve is calculated.
Abstract: (1984). Gel Permeation Chromatography of Polysaccharides: Universal Calibration Curve. Agricultural and Biological Chemistry: Vol. 48, No. 9, pp. 2375-2376.
TL;DR: Calibration in atomic-absorption spectrometry is achieved by means of a concentration gradient chamber using a single concentrated standard solution, irrespective of the shape of the conventionally obtained calibration curve.
TL;DR: A microwave induced plasma emission detector is used as an element-selective detector for gas chromatography and the response per mole appears to be independent of the molecular structure.
Abstract: A microwave induced plasma emission detector is used as an element-selective detector for gas chromatography. The spectrometer, which is fitted with a rapid scanning galvanometer mirror, is used to scan a pre-selected spectral window to provide information in the multi-element mode. This information is used to determine the per mole response of some elements as a function of molecular structure. Despite the low microwave powers employed, the response per mole appears to be independent of the molecular structure. Detection limits and linear dynamic ranges are determined by narrowing the spectral coverage to increase the sensitivity. Calibration curves are linear over several orders of magnitude and detection limits are at the pg/sec levels.
TL;DR: In this article, the Stabilized Temperature Platform Furnace technique with Zeeman background correction was used for the determination of As, Se, Cr, Co and Ni in five Geochemicai Exploration Reference (GXR) samples from the U.S. Geological Survey.
TL;DR: In this article, the effect of several parameters, including line number, order and optical aberrations, has been studied and the results of high resolution for line separation, signal-to-background and signalto-noise ratios, and calibration curve linearity for resonance broadened lines and lines with hyperfine structure are illustrated.
TL;DR: In this paper, the authors proposed an analytical equation for fitting the analytically useful concentration range of atomic absorption calibration curves, where C is the concentration, A the observed absorbance, and K's are coefficients which must be determined during calibration.
TL;DR: In this paper, it was shown that factors such as spectral interference and changing conductivity of the discharge plasma as metal atoms are introduced are not responsible for the nonlinearity and change of slope of calibration curves reported in the literature for determinations made on silver-copper-eold alloys usine a Grimm-type glow-discharge lamp.
Patent•
08 Mar 1984
TL;DR: In this article, the level of liquid in a container, for example an upright cylinder of the kind used to store liquefied gas, is monitored by measuring the resonant frequency of the container and comparing it with a pre-determined standard.
Abstract: The level of liquid in a container, for example an upright cylinder of the kind used to store liquefied gas, is monitored by measuring the resonant frequency of the container and comparing it with a pre-determined standard. The resonant frequency is measured by applying mechanical vibrations, preferably of a frequency up to 1 OkHz, to the container and monitoring the resonant frequency using known methods. The results obtained are compared with the pre-determined standard, which is for example a calibration graph, to determine accurately the degree of filling of the container.
TL;DR: The results of erroneous transformation according to Lineweaver-Burk and to Eadie are compared with the results of non-linear regression by means of three sets of measured data or data given in the literature.
Abstract: The Michaelis-Menten function describes a non linear relationship and is a possible calibration curve in TLC. Usually the linearized forms are used but the problem of uncontrolled error propagation arises from data transformation and hence incorrect calibration. Nonlinear regression analysis is therefore used in this paper. The results of erroneous transformation according to Lineweaver-Burk and to Eadie are compared with the results of non-linear regression by means of three sets of measured data or data given in the literature.
TL;DR: In this article, the analysis of a polymethyl methacrylate sample dissolved in dimethylformamide is performed by using a low-angle laser light scattering photometer attached to a thermal field-flow fractionation channel and a differential refractometer.
Abstract: The analysis of a polymethyl methacrylate sample dissolved in dimethylformamide is performed by using a low-angle laser light scattering photometer attached to a thermal field-flow fractionation channel and a differential refractometer. Relevant theoretical light scattering equations for flow-through operation are outlined. It is shown that the calibration curve of the separation system can be constructed in situ during the course of separation, without using any calibration standard. The average molecular weights as well as the molecular weight distribution curves of the polymer have been determined. The sensitivity of the light-scattering photometer has been measured, and it is compared to that of the differential refractometer in terms of signal-to-noise ratios. The various sources of errors in the molecular weight determination are discussed, and the potential of the coupling for physicochemical studies on the thermal diffusion of polymers is indicated. In spite of some inherent problems, thi...
Patent•
30 Jul 1984
TL;DR: In this article, a calibration curve is corrected so that input signals of the correction time, correction effective time and correction indication of the calibration curve corresponding to an analytical item are sent to a control means 5 by an input means 1.
Abstract: PURPOSE:To reduce economical load, by performing the necessary min. correction curves, by mounting a control means for discriminating the correction effective times of calibration curves corresponding to an arbitary number of analytical items and sending the correction alarm and indication information of the analytical item to be corrected. CONSTITUTION:A calibration curve is corrected so that input signals of the correction time, correction effective time and correction indication of the calibration curve corresponding to an analytical item are sent to a control means 5 by an input means 1. The control means 5 controls a memory means 2 so that the correction time and correction effective time are sotred in said memory means 2 at every analytical item and controls a display means 3 to allow the same to display correction alarm information, correction indicating information and the correction effective time. By this method, because indivisual display is enabled at every analytical item and the excess of the effective time or the completion of correction can be displayed as a table, the necessary min. correction of the calibration curve is enabled, and economical and timewise load can be reduced.
TL;DR: In this article, a staircase modulation wave form is implemented for extended range continuum source AAS (atomic absorption spectrometry) measurements, which improves performance and simplifies the computation of concentrations.
Abstract: A new staircase modulation wave form is implemented for extended range continuum source AAS (atomic absorption spectrometry) measurements, which improves performance and simplifies the computation of concentrations. This wave form facilitates the computation of two absorbances of different sensitivity for every atomization. The resulting two calibration curves allow 4-6 orders of magnitude of concentration to be covered effectively. Calibration curves and concentration error curves are compared for Mn, Zn, Fe, Cu, and Mg with the old bi-Gaussian and the new staircase modulation wave forms. Linearities, sensitivities, and SNR's (signal-to-noise ratios) of the curves obtained by using the two modulation wave forms are compared. In addition, accuracy using the staircase modulation wave form was evaluated by running National Bureau of Standards (NBS) standard reference materials (SRM's). 6 references, 13 figures, 1 table.
TL;DR: It is concluded that different theories used to calculate the sodium ion activity in the concentration range investigated give almost the same results; furthermore, introduction of the liquid junction potential leads to a more nernstian-like slope of the calibration graph.
Abstract: We measured the emf of NaCl solutions (120-160 mmol/L) with a home-built cell in steady-state and with some commercial direct potentiometric analyzers about 20 s after the sample is introduced into the instrument. We compared the results with the theoretical sodium ion activity calculated according to different thermodynamic theories. The slope of the calibration graph was calculated with and without correction for the influence of NaCl concentration on the liquid junction potential of the calomel reference electrode. We conclude that different theories used to calculate the sodium ion activity in the concentration range investigated give almost the same results; furthermore, introduction of the liquid junction potential leads to a more nernstian-like slope of the calibration graph. Measurement of identical NaCl solutions with various commercial analyzers showed different displayed concentrations, presumably because of differences in junction structure, measuring time, and concentration of calibration solutions.
TL;DR: In this paper, the components were determined at the nanogram level by a combination of room-temperature fluorescence with selective excitation and emission, and with fluorescence and phosphorescence calibration curves, it was possible to determine all components in a given mixture without isolation of the components.
Abstract: Nitrogen heterocycles and one polycyclic aromatic hydrocarbon were combined to form various binary and ternary mixtures of the compounds. The components were determined at the nanogram level by a combination of room-temperature fluorescence with selective excitation and emission. With fluorescence and phosphorescence calibration curves, it was possible to determine all components in a given mixture without isolation of the components. For the mixtures investigated, the smallest amount of material that could be determined accurately was about 2.5 ng. 14 references, 5 tables, 2 figures.
TL;DR: In this article, a theoretical model is developed which can be used to predict the effects of velocity profile, viscosity and swirl on the calibration curve of a turbine meter and the effect of different types of integral flow straighteners on turbine meters is also investigated and found to depend on both the number of vanes and their length.
TL;DR: In this paper, different combinations of flow-injection arrangements and detector types are described, to establish a system which levels out this undesirable spreading between the calibration curves, and a necessary condition for attaining a low spread is the use of a spectrophotometric detector especially constructed to minimize refractive index effects.
TL;DR: In this article, a new method of calibration for open tubular column gas chromatography with electron-capture detection is proposed, which combines the operation of solute identification by retention index values and multiple solute calibration into a single method, capable of automation.
TL;DR: In this article, the system γ-aminopropyltriethoxysilane coupling agent on E-glass mat has been analyzed by the use of factor analysis to determine the number of pure components and extract the pure component spectra, to improve the signal-to-noise (S/N) ratio of the collected spectra.
Abstract: The system γ-aminopropyltriethoxysilane coupling agent on E-glass mats has been analyzed by the use of factor analysis to determine the number of pure components and extract the pure component spectra, to improve the signal-to-noise (S/N) ratio of the collected spectra, and to determine the concentration of unknown mixtures. Normalization of the scaling coefficients allows the construction of a calibration curve for the determination of the treating solution concentration by examination of the silane coupling agent on the glass mats.