Calibration curve

About: Calibration curve is a research topic. Over the lifetime, 6552 publications have been published within this topic receiving 95128 citations.

Conical rocket nozzle performance under flow- separated conditions

Abstract: The data points were next normalized for time variance by linear interpolation, and the calibration curve resulting from this data processing procedure is plotted as the dashed overlay curve of Fig. 3. A second digital computer program was written to reconstruct side force during the oscillatory portions of the flow program. The normalized calibration curve of Fig. 3 was programed for digital simulation; at any time point, then, the total pressure integral and reaction force variables were first defined. After normalizing the force integral to a consistent 500-psi chamber pressure and time adjusting, the computer determined the value of total side force diminished by the reaction force from Fig. 3. The final side force was obtained by summing the reaction force component to the previous calculation results. This routine was repeated at each of the remaining time points. Although the final internal aerodynamic frequency response shows a rapid amplitude attenuation at the higher frequencies, the LITVC system internal aerodynamic bandwidth is flat to 20 cps (see Fig. 4). Both phase and amplitude ratio parameters are characteristic of a first-order system with a 20-cps break frequency.

Quantitative Determination of Fenthion in Pesticide Formulations by FT-Raman Spectroscopy

Abstract: The Raman spectrum of the organophosphorus pesticide fenthion is presented, and a novel Fourier transform (FT)-Raman method for the quantitative determination of fenthion in pesticide formulations is proposed. Calibration curves based on Raman intensity and band area at 2951, 1065, 661, and 604 cm-1 were linear (correlation coefficients: 0.991-0.998) in the concentration range of 0.4-4.36 M. Detection limits ranged between 0.14 to 0.36 M and precision from 0.4 to 6.8% relative standard deviation (RSD) (n = 4). Spectra normalization against the 802 cm-1 cyclohexane band proved to be effective in minimizing the effect of excitation intensity fluctuations and sample positioning changes in calibration data, resulting in improved long-term stability of the calibration curves. Results obtained during the analysis of the Lebaycid formulation compare well with those obtained by the gas chromatography (GC) reference method. The proposed FT-Raman method is fast, simple, and safe, avoids sample pretreatment, and minimizes handling of toxic samples.

Calibration and Long-Term Stability of a PIXE Set-Up

Abstract: A general mass calibration procedure of a PIXE set-up is described. As an example, the results of the calibration of the PIXE set-up in Lund are given. For the calibration commercially available standards were used. The parameters of a physical model were adjusted to fit a calibration curve. To decrease errors due to inhomogeneities of the standard foils, the average from four different pieces of each foil was taken. The accuracy of the calibrated system in Lund is estimated to be better than 5% for individual elements and still less for ratios of adjacent elements. For long-term quality control of the results, a special sample has been designed. This consists of a thick silver plate with a small copper spot in the centre. It is very sensitive to small changes in a PIXE set-up. By analysing this sample periodically, mistakes in the arrangement are promptly detected-a feature which is much appreciated in a mixed research, development and routine analysis laboratory. Also a measure of the long-term stability is obtained. For the Lund system, the long-term stability is 2.5% for a homogeneous sample and 4% for a small (inhomogeneous) sample.