System for determining concentration of an electrolyte

• US 5,022,980 A
• Filed: 12/30/1988
• Issued: 06/11/1991
• Est. Priority Date: 12/30/1988
• Status: Expired due to Term

• Current Assignee: Toshiba Corporation
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Takiguchi, Toshio, Tanaka, Akiko
• Primary Examiner(s): Tung, T.
• Application Number:
  US07/292,333
• Time in Patent Office: 893 Days
• Field of Search: 204/401, 204/1 T, 204/416, 204/418, 204/419, 204/400, 204/153.1, 73/1 R, 364/497, 340/501
• US Class Current: 204/400
• CPC Class Codes: G01N 27/4165 for pH meters
• CPC Class Codes: G01N 33/492 Determining multiple analytes

Abstract

A system and method for checking the concentration of an electrolyte in a solution utilizing ion-selective electrodes for sequentially measuring potential levels of a sample solution and a correction solution at selected time intervals. The potential levels of the positive and negative ions in the sample and corrective solutions are then compared with a standard potential level for the correction solution. A procedure determines if an abnormal deviation in the sample solution exists and if this abnormal deviation is caused by the actual concentration of electrolytes in the sample solution or if the abnmormality is caused by an error in measurement. An alarm is sounded to indicate that the abnormality exists and the cause of the abnormality.

Claims

1. A system for determining the concentration of an electrolyte in a solution by measuring the difference between potential levels of the solution containing the electrolyte and a corresponding correction solution, comprising:

ion-selective electrode means responsive to positive and negative ions for sequentially measuring positive and negative potential levels of positive and negative ions in a sample solution and in the correction solution to provide sample data of positive and negative potential levels;

comparing means for comparing at time intervals said positive and negative potential levels of the correction solution and the sample solution with standard potential levels for the correction solution so as to detect any variation;

discriminating means for discriminating which of two variation patterns said any variation indicates;

means for detecting an abnormal variation between the positive and negative potential levels of said sample solution and said correction solution and said standard potential levels of said correction solution; and

means for determining if said abnormal variation is due to said sample solution or due to an error in measurement.

2. A system according to claim 1, further comprising:

alarm sounding means for indicating that the abnormal variation exists.

3. A system according to claim 2, wherein:

the alarm sounding means sounds one alarm when the abnormal variation is due to the sample solution and sounds another alarm when the abnormal variation is due to an error in measurement.

4. A system for determining the concentration of an electrolyte in a solution utilizing a measuring system, the system comprising the steps of:

means for obtaining a test solution having an electrolyte concentration to be measured;

means for measuring positive and negative potential levels of a correction solution having substantially a same composition as the test solution in a normal state for use as standard positive and negative potential levels of the correction solution;

means for storing the standard positive and negative potential levels of the correction solution;

means for measuring positive and negative potential levels of the test solution and the correction solution at time intervals;

means for comparing each measured positive and negative potential level of the test and the correction solutions respectively with the standard positive and negative potential levels of the correction solution;

means for detecting if a variation exists between the standard and measured positive and negative levels of the correction solution;

means for determining whether the positive and negative potential levels of the correction solution measured at time intervals deviate towards one of an opposite polarity with respect to each other and a same polarity with respect to each other.

means for obtaining the concentration of the electrolyte of the test solution as a difference between potential levels of the test solution containing the electrolyte to be measured with the measured potential levels of the correction solution when no variation is detected; and

means for outputting a signal of abnormal results when a variation is detected.

5. A system according to claim 4, wherein the outputting means further comprises:

means for outputting a signal indicating an abnormal measuring system when the positive and negative levels of the correction solution deviate towards the same polarity with respect to each other.

6. A system according to claim 5, wherein the outputting means further comprises:

means for outputting a signal indicating an abnormal sample when the positive and negative levels of the correction solution deviate towards the opposite polarity with respect to each other.

7. A system according to claim 6, wherein the outputting means further comprises:

means for outputting a signal indicating an abnormal measuring system when the positive and negative levels of the correction solution deviate towards the same polarity with respect to each other.

8. A system according to claim 4, wherein the variation of the detecting step is greater than a predetermined value.