Final report on supplementary comparison COOMET.PR-S7: Laser power responsivity (COOMET 599/RU/13)

The National Institute of Standards and Technology (NIST), USA and the All-Russian Research Institute for Optical and Physical Measurements (VNIIOFI), Russia agreed in February 2013 to conduct a comparison on the laser power responsivity at wavelengths of 532 nm, 1.064 μm and 10.6 μm. The aim of this comparison is to assess the equivalence of the laser power responsivity between two laboratories. The comparison was conducted within the COOMET regional metrological organization (COOMET 599/RU/13) and was registered in the BIPM Key…

New app note on sensitive EQE characterization measurements

The landscape of photodetector and solar cell technologies has been rapidly expanded with the emergence of numerous novel material paradigms, including organic semiconductors, perovskites, and two-dimensional (2D) materials. These technology advances directly impact a broad spectrum of applications, from night vision to medical imaging and energy conversion. As materials, device architectures, and manufacturing processes evolve, external quantum efficiency (EQE) is a key metric when comparing devices and competing technologies. Source: Lakeshore…

Calibration of diameter standards (EURAMET.L-K4.2015)

At its meeting in October 2014, the EURAMET TC for Length, decided upon a key comparison on the calibration of diameter gauges, named EURAMET.L-K4.2015. Twenty National Metrology Institutes and one Designated Institute from Europe, Asia and South America participated in this comparison, which was carried out in two parallel groups. Twelve laboratories from EURAMET participated in group 1, while ten laboratories from EURAMET and two laboratories from GULFMET and SIM participated in group 2. To provide the link three laboratories, CEM,…

Overcoming the challenges of cryogenic magnetic field measurements

With the growth in use, complexity, and strength of superconducting magnets, the need to characterize the fields they produce is growing as well. There are a multitude of complicating factors that make this a challenging prospect. There are many options for taking a measurement in this situation, but how do you know whether the reading you take it really measuring what you think you’re measuring? Source: Lakeshore…

Automatic alignment technique for the suspended coil in the joule balance

An automatic alignment technique was developed for the joule balance to reduce the uncertainty caused by alignment errors. Using the flexures and decoupling structure of the suspended coil, the proposed alignment system can automatically recognize the linear relationship between the initial position and posture of the suspended coil when the current is off, and its parasitic horizontal linear and angular displacements when the current is on. Subsequently, several actuators including mini-motors and an X – Y stage are controlled to adjust…

International comparison CCQM-K74.2018: Nitrogen dioxide, 10 μmol mol-1

The CCQM-K74.2018 comparison evaluated the level of compatibility of nitrogen dioxide (NO 2 ) in nitrogen standards at nominal amount fractions of 10 μmol/mol provided by National Metrology Institutes. Fourteen laboratories participated in the comparison, submitting two standards each, with comparative measurements and comparison coordination undertaken by the BIPM. Measurements at the BIPM were performed from July 2018 to May 2019. The key comparison reference values (KCRV) for each submitted standard were established at three different times during the measurement period…

Supplementary comparison APMP.RI(I)-S1 of standards for absorbed dose to water in 60 Co gamma radiation at radiation processing dose levels

Four national standards for absorbed dose to water in 60 Co gamma radiation at the dose levels used in radiation processing have been compared over the range 0.1 kGy to 50 kGy using alanine dosimeters of the Office of Atoms for Peace (OAP) as transfer dosimeters. The comparison was piloted by the OAP who also participated. Two laboratories from the original six were forced to withdraw due to equipment problems. The results at low doses (0.1 kGy) showed a much wider…

International comparison CCQM-K117 ammonia

At the highest metrological level, ammonia gas standards are commonly prepared gravimetrically as Primary Standard Mixtures or using a dynamic standard. This international key comparison addressed the measurement of the amount fraction ammonia in nitrogen, to support calibration and measurement services for mainly environmental applications. The nominal amount fraction was 14 μmol mol -1 . The results in this Track C key comparison on the composition of biogas are generally good. To reach the main text of this paper, click on Final…

Primary standard for traceability in low liquid hydrocarbon fuel flow rates

We developed a primary standard for low liquid hydrocarbon flow rates that works on light oil (diesel), kerosene and industrial gasoline. To achieve a calibration accuracy of below 0.1% over a wide flow range from 0.02 L h −1 to 100 L h −1 as required by the industry, this primary standard adopts the gravimetric calibration method performing static weighing with flying-start-and-finish, incorporating a compactly designed conical rotating double-wing diverter for the upper flow range (1 L h −1 to 100…

How does a demagnetizer work? YouTuber uses our teslameter to find out

In the words of our favorite YouTuber, “I have always wondered how the inexpensive magnetizer-demagnetizer tool works. What’s inside it? And why are there stairs inside the demagnetizer opening?” Watch Brainiac75’s latest video, in which he sets out to answer these questions with the help of our F71 teslameter (while also offering a preview of the instrument’s forthcoming live plotting feature): Source: Lakeshore…