Abstract: A drilling rate and depth monitor is provided for determining the rate in which apertures are formed in a workpiece using an electro-chemical machining process. The drilling rate and depth monitor is particularly useful where the rate of aperture formation is extremely slow, i.e., less than one-thousandths of an inch per second. The drilling rate includes a position sensor coupled between a workholder and a movable member supporting a plurality of cathodic drilling tubes which yields a depth signal proportional to the distance between the drilling tubes and the surface of the workpiece. Differentiation means are responsive to the depth signal for producing a drilling rate signal and display means are provided for both the drilling rate and drilling depth.

Abstract: Disclosed is an apparatus for storing blood gas quality control reagent comprising a first variable volume, gas impermeable container for receiving the reagent. The reagent is stored exclusively in the liquid phase therein. A valved exit passageway emanates from the container which container is situated in a second container surrounding the first, a space being present therebetween and a compressed gas situated in the space. Upon opening the valve, the compressed gas decreases the volume of the first container and reagent is expelled through the exit passageway. The present device is uneffected by changes in ambient temperature since the reagent is stored exclusively in the liquid phase. The device is reusable since a portion of the reagent may be expelled without contamination of the remaining contents.