The devices calibrated most frequently by the acoustical measurement services at the National Institute of Standards and Technology (NIST) over the 50-year period from 1963 to 2012 were one-inch condenser microphones of three specific standard types: LS1Pn, LS1Po, and WS1P. Due to its long history of providing calibrations of such microphones to customers, NIST is in a unique position to analyz...

The analysis of organic solvents by ICP-MS is challenging due to their high carbon content and volatility. Naphthas are an important class of organic liquids produced in the petrochemical industry, byproducts of the crude-oil refining process. Because they are organic based and have a variety of compositions, naphthas present a special challenge for ICP-MS analysis: the carbon causes polyatomic...

We report here a quick and inexpensive method for preparing standards of known fluorochrome content for calibration and quantitation of flow cytometry fluorescence signals. Erythrocyte ghosts prepared by hypotonic lysis are filled with solutions containing fluorescently labeled dextran. Standards prepared by this technique have a narrow range of fluorescence and a linear response of fluorescenc...

A new calibration protocol, developed by the AAPM Task Group 51 (TG-51) to replace the TG-21 protocol, is based on an absorbed-dose to water standard and calibration factor (N(D,w)), while the TG-21 protocol is based on an exposure (or air-kerma) standard and calibration factor (N(x)). Because of differences between these standards and the two protocols, the results of clinical reference dosime...

In the United States, there are several federal agencies interested in the effects of UV radiation, which has resulted in the establishment of UV monitoring programs each with their own instrumentation and sites designed to address their specific needs. In 1993, participating agencies of the U.S. Global Change Research Program organized a UV Panel for coordinating the different agencies’ progra...

background: absolute dosimetry of external beam radiotherapy is carried out by the use of ionization chambers. these chambers must be calibrated at a standard dosimetry laboratory before any use in clinical dosimetry. the secondary standard dosimetry laboratory of iran (ssdl) has the duty of calibrating the ionization chambers used in radiotherapy centers in iran. materials and methods: the pre...

The recently developed 222Rn emanation standards that are based on polyethylene-encapsulated 226Ra solutions were employed for a first field-measurement application test to demonstrate their efficacy in calibrating passive integral radon monitors. The performance of the capsules was evaluated with respect to the calibration needs of electret ionization chambers (E-PERM®, Rad Elec Inc.). The enc...

Experimental measurements require calibration to transform measured signals into physically meaningful values. The conventional approach has two steps: the experimenter deduces a conversion function using measurements on standards and then calibrates (or normalizes) measurements on unknown samples with this function. The deduction of the conversion function from only the standard measurements c...

a r t i c l e i n f o Keywords: Calibration free laser-induced breakdown spectroscopy (CF-LIBS) Multi-element analysis Oxides The quantitative determination of oxide concentration by laser-induced breakdown spectroscopy is relevant in various fields of applications (e.g.: analysis of ores, concrete, slag). Calibration free laser-induced breakdown spectroscopy and the multivariate calibration ar...