The parallel-plate free-air ionization chambers are used for X-rays air-kerma rate standards at National Metrology Institute of Japan (NMIJ), National Institute of Advanced Industrial Science and Technology (AIST). The diaphragms are used to free-air chambers to fix the air volume of ionizing region in chambers. It means that absolute air-kerma rates are defined for collimated x-ray beams, beca...

The Re-Os isotopic system is currently limited as a chronometer because of the lack of accurate gravimetric standards for Os spike calibration and uncertainty of the Re half-life, which is also dependent on the accuracy of Os spike calibration. We demonstrate that the concentration of an Os spike can be calibrated accurately to 60.2%. The accuracy of this calibration was achieved by using a hig...

BACKGROUND Protein profiling by surface enhanced laser desorption ionization-time of flight-mass spectrometry (SELDI-TOF-MS) is gaining importance as a diagnostic tool for a whole range of diseases. This report describes a QC procedure, which acts prospectively by checking the calibration before starting profiling experiments. METHODS A well-defined protocol for calibration of the Protein Bio...

Currently, in civil engineering, high performance concrete i.e. concretes whose minimum compression strength is equal or more than 65 MPa are increasingly used. Side effect of it is need for determination of their construction strength. In particular, recently built high performance structures suffer from sampling of drill cores. Therefore, noninvasive impact hammers – to be specific Schmitt im...

Modern X-ray units register the air kerma-area product, PKA, with a built-in KAP meter. Some KAP meters show an energy-dependent bias comparable with the maximum uncertainty articulated by the IEC (25 %), adversely affecting dose-optimisation processes. To correct for the bias, a reference KAP meter calibrated at a standards laboratory and two calibration methods described here can be used to a...

The National Bureau of Standards (NBS) is beginning to provide a mechanism for traceability for a number of NDE measurement procedures, an activity that is expected to have a significant, positive impact on the reproducibility and accuracy of NDE measurements. Much of the NDE standards activity has been in ultrasonics and acoustic emission, this effort leading to calibration services for ultras...

At the National Institute of Standards and Technology (NIST), the U.S. representation of the ohm is based on the quantum Hall effect, and it is maintained and disseminated at various resistance levels by working reference groups of standards. This document describes the measurement systems and procedures used to calibrate standard resistors and current shunts of nominal decade values in the res...

− A growing number of measurements in commercial and industrial sector need to refer to the traceability to the national (and international) standards. Instrument and reference standards calibration is resource and time consuming. Since many of the available digital instruments provide some communication interfaces and the internet-enabled metrology is rapidly developing in the recent years, it...

' Several perplexing questions involving standardization techniques surface when ultraviolet spectrophotometry is used for the determination of unknown ribonucleic acids isolated from tissue sources. One must consider the effect of hydrolysis on total absorbance, nucleotide makeup of a ribonucleic acid versus molar absorptivity and additivity of riucleotides on total measured absorbance. Experi...

Within recent years, ganglioside patterns have been increasingly analyzed by MS. However, internal standards for calibration are only available for gangliosides GM1, GM2, and GM3. For this reason, we prepared homologous internal standards bearing nonnatural fatty acids of the major mammalian brain gangliosides GM1, GD1a, GD1b, GT1b, and GQ1b, and of the tumor-associated gangliosides GM2 and GD2...