Calibration curve

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

Conversion of logarithmic channel numbers into relative linear fluorescence intensity.

Abstract: We describe a simple, reproducible, and generally applicable method to assess the performance of log amplifiers by using a fluorescent sample that provides multiple peaks of different intensities. The channel differences between multiple peaks are used to evaluate the logarithmic behavior of the fluorescence signal amplifier on the flow cytometer. A calibration curve can be created to correct the channel numbers for deviations from true logarithmic behavior and then convert data into relative linear intensities. By using these linear fluorescent intensities, we compared the capacity of different antisera against HIV-1 (human immunodeficiency virus type 1) peptides to inhibit the binding of HIV-1 to CEM, a CD4-positive T-cell line. A wide range of applications for this calibration procedure can be envisioned and the method is valuable for monitoring instrument performance over time.

Calibration Transfer and Measurement Stability of Near-Infrared Spectrometers

Abstract: Near-infrared (NIR) spectroscopy has been widely accepted as a quantitative technique in which multivariate calibration plays an important role. The application of NIR to process analysis, however, has been largely limited by a problem identified as calibration transfer, the attempt to transfer a well-established calibration model from one instrument (e.g., located in the central laboratory) to another instrument of the same type (e.g., located on an industrial process). A calibration transfer method called piecewise direct standardization (PDS) is applied to a set of gasoline samples measured on two different NIR spectrometers. On the basis of the measurement of a small set of transfer samples on both instruments, a structured transformation matrix can be determined and applied to transform spectra between two instruments, enabling the transfer of calibration models. The effect of spectrum preprocessing on standardization is studied with the use of a set of gasoline samples. In a separate study, the day-to-day instrument variation as observed from the change in the polystyrene spectrum is related to the prediction of moisture, oil, protein, and starch content in corn samples, and then the possibility of using such generic standards to replace real samples in a transfer set is explored. In all cases, a standard error for prediction comparable to full set cross-validation is obtained through standardization.

A Geiger-Muller counter for measuring the beta-ray activity of liquids, and its application to medical tracer experiments.

Abstract: A G-M counter of the jacketed tube type for β-ray measurements on liquid samples is described, together with a convenient means of mounting in a lead shield. It is shown that the counting rate obtained when the counter is filled is proportional to the concentration of radioactive substance in the solution. Methods for applying corrections for errors due to dead time of the counter and for variations in specific gravity of the solution are given, together with a calibration curve showing the absolute efficiency of the counter for various radioactive isotopes. The counter has proved useful for measurements of the radioactivity of whole blood, plasma, urine, etc., in medical tracer experiments.