Abstract: A carrier supporting multiple filters is inserted jointly with the filters into an air sampler. The carrier includes an indexing structure to ensure correct positioning within the air sampler. A memory device physically associated with the carrier stores sample collection data provided by the air sampler. The stored data can be read by a read/write station at a lab, and transmitted to a processor. The processor also receives a weight reading from a communicating balance for each collected sample, and calculates therefrom mass concentration for each sample.

Abstract: A suspension system for an inertial balance constrains the weighing platform when oscillated to undergo uniform linear motion, thereby ensuring high measurement accuracy. The suspension system includes a supporting framework and a first plurality of elongate elastic support members for suspending the weighing platform from the supporting framework. The elongate support members are disposed in a common plane when the weighing platform is at rest and their inner ends intersect at a first common point to which the weighing platform is firmly linked. A second plurality of such elongate support members is similarly disposed in a second common plane parallel to but spaced from the first common plane. A stiff connecting rod joins the intersection points of the two pluralities and also serves to support the weighing platform and, in conjunction with a feedback system, serves to induce and maintain the weighing platform in oscillation at a resonant frequency dependent upon mass loading.

Abstract: Improved shaped glass elements having very low thermal coefficients of elastic modulus are provided for use as measuring means in balances for determining the mass of objects with a high degree of resolution. A particularly preferred form of the invention id fabricated from a glass consisting of 60.6% SiO.sub.2, 14.7% B.sub.2 O.sub.3, 8.94% Al.sub.2 O.sub.3, 4.72% Na.sub.2 O and 10.98% BaO, by weight.

Abstract: A suspension system (11) for effectively decoupling an oscillating element microbalance (10) from its environment employs longitudinally extending suspension members axially aligned with an instantaneous center of rotation (S) of the microbalance. In a preferred embodiment, the microbalance includes a tapered elongate elastic element (12) having an elliptical cross section and the suspending members comprise a torsion bar arrangement (20, 22) oriented parallel to the major axis (HD) of the elliptical cross section. The suspension system minimizes vibrational losses from the microbalance while at the same time rendering environmental noise ineffectual.