PRELIMINARY COMPARISON RESULTS OF Nano3 LINE SCALES SHIPPED.

In a meeting held at Bureau International des Poids et Mesures (BIPM) in June 1998, the Consultative Committee for Length (CCL) and Working Group on Dimensional Metrology (WGDM)-7 decided to conduct preliminary comparisons for five different types of artifacts. Among the five different artifacts were the Nano3 Line scales. Fourteen national laboratories around the world participated in this comparison with Physikalisch-Technische Bundesanstalt (PTB), Germany, acting as the Pilot Laboratory. These comparisons will help to establish the degree of metrological equivalence between the participating nations. The NIST Nano-Scale Metrology Group completed measurements for this key international comparison of line scales and sent the final measurement reports to PTB. Two 280 mm scales, one Zerodur and one quartz, were measured on the NIST Line Scale Interferometer (LSI). These scales were shipped around to the participating laboratories in a precision shipping container, which was equipped with temperature, humidity, and shock sensors; the outputs from these sensors were recorded by the on-board data logger.