Abstract: An optically based liquid level (liquid-vapor) detector for use with a window having a substantially planar side facing the liquid-vapor side and a substantially planar side positioned parallel to the liquid-vapor side facing the outside. The detector comprises a light source positioned on the outside of the window to direct its light through the outside planar side to the inside planar liquid-vapor side and a light detector positioned on the outside of the window to receive light transmitted from the source and returned from the planar liquid-vapor window side. The detector further includes electronic means for detecting the light intensity change affecting the transducer, from the condition of liquid on the liquid-vapor side, to the condition of vapor on the liquid-vapor side of the window, whereby an action or signal is generated in response to such change.

Abstract: A gage having sensors for observing temperature and pressure. The gage includes a display and an internal computer. A data cartridge separate from the gage but with an electrical plug type connection to it is supplied. The data cartridge has a non-volatile memory on which is stored data relating pressure and saturation temperature of a volatile refrigerant. A program is stored within the gage. The program contains instructions for measuring temperature and pressure from a source, retrieving from the data cartridge saturated temperature data corresponding to the observed pressure, calculating superheat or subcooling and displaying in sequence the observed pressure in absolute or gage terms, the corresponding saturated temperature, the observed temperature and the superheat or subcooling.

Abstract: A miniaturized biological assembly provides a miniature capillary environment in which a liquid medium containing microscopic-size particulate material can be placed for study under a microscope. The assembly includes components which do not wet relative to the liquid medium. A sample chamber and second chamber are disposed adjacent one another to allow a selective exchange of material, such as nutrients, between the two chambers. The assembly provides an environment that can contain the liquid medium and material for a period of time sufficient to enable observation while preventing deterioration of the medium and material.