Abstract: Apparatus for recovering from a filter element a dry cleaning fluid, the vapor of which is more dense than air, is disclosed. The apparatus comprises a chamber, a support for a filter cartridge, a heating element, and a cooling element located below the heating element.

Abstract: This invention is an apparatus for making solutions of chemicals of specified molarity, normality, molality or weight percentage corrected, as necessary, for water of hydration in the solute. By means of an input-output device using a programmed instruction format, the desired chemical, the type of solution wanted, its concentration, and its volume are specified. An electronic balance with TARE capability repeatedly produces an output signal of the weight W of solute plus any solvent within a container in which the solution is to be mixed less the weight of the container. Apparatus are provided for calculating and storing the weight TW which is the total weight of the solute plus solvent which will result in a solution of the type and concentration of solution specified for the amount of solute placed on the balance. If the total volume of solution of the desired type and concentration of solution is specified, apparatus are provided for determining the amount of solute required.

Abstract: A multi chambered slide is disclosed having a base plate, a plurality of spaced apart boundaries attached to the base plate, each contiguous pair of boundaries defining an area within which a liquid sample may be contained, each boundary having a pair of spaced apart elements between which is defined a boundary zone for containing any sample that may leak from the area defined by a pair of boundaries, each element being of substantially uniform thickness and being coated with an adhesive and a cover plate attached to the spaced apart elements of the boundaries to define a plurality of volumetric chambers into which liquid samples may be introduced.

Abstract: An apparatus for making dilutions of a sample with a diluent to a predetermined dilution factor f by weight of the diluent is disclosed. A scale with TARE capability produces an output signal of the weight W of a sample within a container less the weight of the container. A dilution factor control is provided for setting the predetermined dilution factor f. Apparatus is provided for calculating and storing the value TW=W/f which is the total weight of the sample plus the weight of the diluent which is required to dilute the sample to the predetermined dilution factor f. A pump is connected between a reservoir of diluent and the container for the sample for pumping the amount of diluent into the container which is required to dilute the sample to the predetermined weight dilution factor f. The scale provides a continuous output of the weight W of the sample plus diluent in the container at any instant in time. Apparatus is provided for calculating when TW-W=0.

Abstract: A method for determining the concentration of an unknown bacterial solution using only a single bacterial growth plate for the determination. The method comprises depositing a varying amount of bacterial solution on the surface of a solidified agar plate by continuously varying the amount of solution deposited in the shape of a spiral on the agar which is in a rotating Petri dish. Thus, a higher concentration of bacteria per unit length occurs at the center of the spiral and a decreasing concentration per unit length at the edge of the plate. The plate is then incubated and the colonies in a predetermined area of the plate are counted in order to determine the concentration of the unknown solution. The bacterial colonies in a predetermined area may be counted by interrupting a light or laser beam incident to a photodiode, the light being interrupted by the presence of a bacterial colony.