| 摘要 |
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 (24) using a programmed instruction format, the desired chemical, the type of solution wanted, its concentration, and its volume are specified. An electronic balance (12) with TARE capability repeatedly produces an output signal of the weight W of solute plus any solvent within a container (20) in which the solution (11) is to be mixed less the weight of the container. A programmed microprocessor (400) is 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, the microprocessor calculates the amount of solute required. Apparatus (34, 40, 42 and 46) are provided for controlling the flow of solvent between a source (36) and the container (20) for causing the flow of solvent into the container when TW-W is greater than zero and to stop the flow of solvent into the container when TW-W=0. The microprocessor (400) performs calculations which are used to prevent overfilling the container (20). |
