Ion-measuring apparatus for use in process

• US 5,004,998 A
• Filed: 12/07/1989
• Issued: 04/02/1991
• Est. Priority Date: 12/14/1988
• Status: Expired due to Fees

• Current Assignee: Horiba Limited
• Original Assignee: Horiba Limited
• Inventors: Horii, Yoshio
• Primary Examiner(s): NOT, DEFINED
• Application Number:
  US07/447,221
• Time in Patent Office: 481 Days
• Field of Search: 204/401, 204/416, 204/433, 204/412, 204/406, 364/497, 364/551.01, 324/438, 324/512, 324/537, 73/1 R, 340/506, 340/537, 340/507
• US Class Current: 340/507
• CPC Class Codes: G01N 27/403 Cells and electrode assemblies

Abstract

An ion-measuring apparatus for use in processes, characterized by comprising 3 or more ion-measuring electrodes for measuring a same one ion contained in a same one sample, means for computing a mean value of measured values obtained by means of said ion-measuring electrodes, an indicating portion for indicating the computed result, means for judging an existence of an abnormality in the ion-measuring electrodes and an alarm for emitting a maintenance alarm when the abnormality occurs in any one of the ion-measuring electrodes so that the ion-measuring electrode, which has been judged to be abnormal, may be excluded to continue a measurement by means of remaining ion-measuring electrodes.

Claims

1. An ion measuring apparatus for the monitoring of a sample from a production process, comprising:

a plurality of ion measuring electrodes for respectively measuring the ion content of the sample and providing an output measurement signal based on outputs from each of the electrodes;

means for determining a failure of one of the electrodes, and

means for excluding the failed electrode output form the output measurement signal

6. The ion measuring apparatus of claim 1 wherein the ion measuring electrodes are in the form of sheet electrodes.

7. The ion measuring apparatus of claim 1 wherein the ion measuring electrodes are in the form of rod-like composite electrodes integrally comprising an ion-selective electrode and a reference electrode.

8. The ion measuring apparatus of claim 7 including a second alarm for providing an indication of a second failure of an electrode and means for enabling a second alarm mode of operation after the initial detection of a failure.

9. The ion measuring apparatus of claim 1 further including an alarm that is responsive to a detection of a failure of an electrode.

10. An ion measuring apparatus for continuously monitoring samples form a production process, comprising:

a plurality of duplicate ion measuring electrodes for measuring a predetermined ion concentration characteristic of the sample;

means for calibrating each of the ion measuring electrodes;

first means of determining any failure of the electrodes;

second means, in response to the determination of a failure by the first means, for determining whether a sufficient number of electrodes are still accurately measuring the sample, and

means for excluding the failed ion measuring electrode and continuing the measurement of the sample when the second determining means indicates that an accurate measurement can be continued with the remaining electrodes.

2. The ion measuring apparatus of claim 11 further including a supplemental ion measuring electrode whose output signal is utilized to replace the output of the failed electrode.

3. The ion measuring apparatus of claim 2 further including means for automatically activating the supplemental ion measuring electrode upon a failure of an electrode.

4. The ion measuring apparatus of claim 2 wherein an initial set of ion measuring electrodes are provided and means are provided to replace the set of ion measuring electrodes with a supplemental set of ion measuring electrodes upon detection of a failure of any one of the set of ion measuring electrodes.

5. The ion measuring apparatus of claim 2 further including means for moving the supplemental ion measuring electrode into the sample after detection of a failure.

11. The ion measuring apparatus of claim 10 wherein the plurality of duplicate ion measuring electrodes includes at least one replacement electrode and means for activating the replacement electrode to take the place of the failed electrode.

12. The ion measuring apparatus of claim 10 further including means responsive to the failure determining first means for providing an alarm signal.

13. The ion measuring apparatus of claim 10 further including a supplemental ion measuring electrode whose output signal is utilized to replace the output of the failed electrode.

14. The ion measuring apparatus of claim 10 wherein the ion measuring electrodes are in the form of sheet electrodes.

15. The ion measuring apparatus of claim 10 wherein the ion measuring electrodes are in the form of rod-like composite electrodes integrally comprising an ion-selective electrode and a reference electrode.

16. An ion measuring apparatus for the monitoring of a sample from a production process, comprising:

a plurality of ion measuring electrodes for respectively measuring the ion content of the sample and providing an output signal from each of the electrodes;

means for computing a mean value signal from the output signals of each of the electrodes as a measurement signal;

means for judging a failure of any one of the electrodes to profile a reliable output signal;

means for excluding the failed ion measuring electrode output signal from the mean value computation;

warning means for providing an indication of a failure, and

means for using he output signals from the remaining ion measuring electrodes after the failure judgment to maintain a continuous measurement signal, whereby the production process can continue despite the failed electrode.

17. The ion measuring apparatus of claim 16 wherein the warning means includes a secondary alarm that is enabled after an initial alarm.

18. The ion measuring apparatus of claim 16 further including means for determining whether a sufficient number of electrodes ar still accurately measuring the sample.

19. The ion measuring apparatus of claim 16 further including a supplemental ion measuring electrode whose output signal is utilized to replace the output of the failed electrode.

20. The ion measuring apparatus of claim 19 further including means or automatically activating the supplemental ion measuring electrode upon a failure of an electrode.

21. The ion measuring apparatus of claim 20 further including means for moving the supplemental ion measuring electrode into the sample after detection of a failure.

22. The ion measuring apparatus of claim 16 wherein the ion measuring electrodes are in the form of sheet electrodes.

23. The ion measuring apparatus of claim 16 wherein the ion measuring electrodes are in the form of rod-like composite electrodes integrally comprising an ion-selective electrode and a reference electrode.

24. The ion measuring apparatus of claim 16 wherein an initial set of ion measuring electrodes are provided and means are provided to replace the set of ion measuring electrodes with a supplemental set of ion measuring electrodes upon detection of a failure of any one of the set of ion measuring electrodes.