Procedure for high precision density determinations by hydrostatic weighing

Abstract

The re are se ve ral s implifica tions whi ch c an be made in t he performance of the hydrostatic experime nt wh ic h le ad to more re produc ibl e res ults. Th e operation of s in gle-pan two-knife balances is di sc ussed , a nd s imp le mod ifi c at ions suggested to adapt it to h ydros tati c work _ A data philosophy is Ilrese nted wh ic h will be partic ularly a pplica bl e to a generation of now-d evelopin g forc e measuring ms trum e nts whe n used in hydros tati c work. A s im pli fi ed form ul a for a ir de nsity is prese nted a nd a formu la for es timat in g day-to-day variabi lit y in th e d e ns ity of wate r. A simpl e ba la nce ca lib ration procedure is prese nted in a n appendi x, and simpl ifi ed me th od s of fabri catin g s us pen sio n wires a nd degass in g sa mple s urfaces are d escribe d. T he use of th ese tec hniqu es is ill us trated by mea s ure me nts on s ilico n c rysla ls wh ic h indi cate process re prod uc ibilil y of a standard d e viati o'ri to a bo ut one part per mill ion.Key Word s: Air den s it y, ba la nce, bal a nce c ali bration , ba la nce e quilibrium , ba la nce se ns iti vi ty, de ns ity , double s ubs tituti on we ighin g, hydrostatic ba la nce, hydros tati c we ighin g, s ilicon d e ns ity , s ub s titution ba lance , volum e tri c meas ure me nt , water de ns it y, wate r we ig hin g.

Analysis of density changes in plutonium observed from accelerated aging using Pu-238 enrichment

“…Between measurements, the samples were stored in a helium-filled incubator at 50°C. The equipment closely matches a design used by Bowman et al 2 and uses about 200 ml of Fluorinert Electronic Liquid FC-43 as the immersion fluid as shown in Figure 2. Prior to each measurement, the system is calibrated using NIST glass (SRM 1827A) and a tantalum specimen as standards.…”

Barium sodium niobate (Ba(4+x)Na(2−2x)Nb10O30): crystallographic data and thermal expansion coefficients

“…The hydrostatic densities were measured on sample WB-797-D, which was neither poled nor detwinned, using a single-pan balance with 10 pg sensitivity, a 0.001" diameter untreated tungsten wire suspension and water as the immersion liquid. Outgassing, water density, and air buoyancy correction calculations were performed as described by Bowman & Schoonover (1967). All replicates were completely independent as defined therein.…”

Physical Property Changes in Aging Plutonium Alloys

“…The immersion density equipment closely matches a design used by Bowman et al [6] and uses about 200 ml of Fluorinert Electronic Liquid FC-43 as the immersion fluid. Prior to use, the system is calibrated using NIST glass (SRM 1827A).…”