Titration apparatus with control means

• US 4,203,156 A
• Filed: 12/27/1978
• Issued: 05/13/1980
• Est. Priority Date: 12/27/1977
• Status: Expired due to Term

• Current Assignee: Mitsubishi Kasei Corp. (Mitsubishi Chemical Group Corp.)
• Original Assignee: Mitsubishi Kasei Kogyo Kabushiki Kaisha
• Inventors: Ishikawa, Seiji
• Primary Examiner(s): Kaplan, G. L.
• Application Number:
  US05/973,562
• Time in Patent Office: 503 Days
• Field of Search: 364/497, 364/500, 364/579, 204/195 T, 204/1 M, 324/29
• US Class Current: 700/267
• CPC Class Codes: G01N 27/44 using electrolysis to generate a reagent, e.g. for titration
• CPC Class Codes: G01N 31/164 by electrical or electrochemical means
• CPC Class Codes: Y10T 436/116664 with automated titrator

Abstract

In a titration controlling method and apparatus wherein variations of a titration system caused by intermittent titrations are successively detected electrically, and the quantity of each intermittent titration is controlled by an electric signal obtained by the detection until an end point is reached. According to the present invention, the quantity of each intermittent titration is determined by dividing the quantity of the immediately prior titration, which has been memorized, by the variation of the titration system caused by the immediately prior titration.

Claims

1. A titration controlling apparatus comprising an electrolytic cell including a pair of electrolytic electrodes and a detecting electrode;

first analogue memory device for temporarily storing an electric signal obtained from the detecting electrode;

a subtractor for subtracting said stored electric signal from an electric signal immediately following said electric signal;

a division circuit receiving the output of the subtractor as a dividend;

a second analogue memory device for temporarily storing the output of the division circuit;

a third analogue memory device for temporarily storing the output of the second analogue memory device and for delivering an output to the division circuit as a divisor; and

a voltage/current converter receiving the output of said second analogue memory device for supplying an electrolytic current to the electrolytic electrodes in the electrolytic cell.

2. A titration controlling apparatus as set forth in claim 1 which further comprises means responsive to the outputs of said second and third analogue memory devices for determining the end point of the titration.

3. A titration controlling apparatus comprising an electrolytic cell including a pair of electrolytic electrodes and a detecting electrode, data-processing means, a first voltage/frequency converting means for converting an output from said detecting electrode into a pulse train, a first signal coupling means for optically coupling an output of said first voltage/frequency converting means to an input of said data-processing means, electrolytic means for intermittently passing a controlled electrolytic current across said electrolytic electrodes, second signal coupling means for optically coupling an output of said data-processing means to an input of said electrolytic means, second voltage/frequency converting means for converting an electrolytic current signal from said electrolytic means into a pulse train, and a third signal coupling means for optically coupling an output of said second voltage/frequency converting means to another input of said data-processing means, said data-processing means further comprising a first operational member which receives the output from said detecting electrode through said first signal coupling means each time when an intermittent electrolysis is carried out in said electrolytic cell, to calculate and store a variation between two successive outputs from the detecting electrode, a second operational member wherein the quantity of electricity passed in the course of an immediately prior electrolysis is divided by said variation between the two successive outputs each time when an intermittent electrolysis is carried out in said electrolytic cell, whereby to preset the quantity of electricity for the immediately subsequent electrolysis, a third operational member which compares the preset quantity of electricity with an actual quantity of electricity passed through said electrolytic means to deliver an electrolysis controlling output when both of said quantities are equal thereby terminating the electrolytic current of each intermittent titration, a fourth operational member which terminates the entire titration upon finding an inflection point in a variation curve exhibiting variation caused by each intermittent titration, and a fifth operational member which integrates the quantity of electricity passed through the electrolytic cell and displays the integrated result.

4. A titration controlling apparatus as set forth in claim 3 wherein each of said photocoupler comprises a luminous diode and a phototransistor or a photodiode.