Calibration curve

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

Sampling and Analysis

Abstract: Publisher Summary This chapter discusses sampling and analysis. In atmospheric analyses, the mass or concentration of the desired analyte is not measured directly. Instead, a numerical value of a physical or chemical property for the analyte, which can then be correlated with either mass or concentration, is obtained. The relationship between the measured physical or chemical property ( X i ) and the quantity ( q i ) for analyte species ( i ) is given by an analytical calibration function X i = f i ( q i ). If X i is determined for a series of standards of different known masses or concentrations, these results establish the analytical calibration curve, that is, the relationship between the analytical signal and the analyte mass or concentration. The choice of an appropriate calibration technique is affected by the analytical method, potential interferences in the sample matrix, the number of samples to be analyzed, the degree of accuracy necessary for the data's intended use, and the relative magnitude of the error contributed by the measurement process compared to combined errors from sampling, sample preparation, and data reduction. Knowledgeable interpretation of trace atmospheric measurement data is an important factor in a good-quality assurance program, and greater recognition of this principle would prevent considerable confusion.

The calorimetric calibration qf idifferential scanning calorimetry cells

Abstract: In this paper it is shown that in many cases enthalpy determinations can be carried out with a precision c 1%. The influences of various sample and instrumental properties are described. The enthalpies of 24 compounds with 30 phase changes (polymorphic transitions or melting points) were redetermined. Twelve of the compounds with 15 transitions in the temperature range 0-67O’C are selected and recommended for calorimetric DSC calibration. The linearization of the calibration curve as stated by the manufacturer of the instrument employed was fully confirmed.

Method of calibrating a network analyzer

Abstract: For calibrating a network analyzer, calibration measurements are successively performed in any desired order on three different calibration standards connected between the two test ports; the first calibration standard is a two-port circuit all of whose complex scatter parameters are known and which is, for example, implemented by a direct connection of the two test ports; the second calibration standard is an attenuator of random transmission but known reflection; the third calibration standard preferably is a two-port circuit exhibiting random reflection which, however, is equal on both sides and different from the reflection of the second calibration standard.

Spectral Interference Elimination in Soil Analysis Using Laser-Induced Breakdown Spectroscopy Assisted by Laser-Induced Fluorescence

Abstract: The complex and serious spectral interference makes it difficult to detect trace elements in soil using laser-induced breakdown spectroscopy (LIBS). To address it, LIBS-assisted by laser-induced fluorescence (LIBS-LIF) was applied to selectively enhance the spectral intensities of the interfered lines. Utilizing this selective enhancement effect, all the interference lines could be eliminated. As an example, the Pb I 405.78 nm line was enhanced selectively. The results showed that the determination coefficient (R2) of calibration curve (Pb concentration range = 14–94 ppm), the relative standard deviation (RSD) of spectral intensities, and the limit of detection (LOD) for Pb element were improved from 0.6235 to 0.9802, 10.18% to 4.77%, and 24 ppm to 0.6 ppm using LIBS-LIF, respectively. These demonstrate that LIBS-LIF can eliminate spectral interference effectively and improve the ability of LIBS to detect trace heavy metals in soil.

Calibration method for flow cytometry using fluorescent microbeads and synthesis thereof

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.