Apparatus for electrochemical measurements
First Claim
1. A device for measuring chemical characteristics of a liquid, said device comprising:
- a housing having upper and lower end surfaces;
a longitudinally extending channel in said housing terminating at one end thereof at least upper surface of the housing and adapted to receive a capillary tube containing a sample of the liquid;
an indicating electrode located about the longitudinal axis of said channel, with said indicating electrode having a tip projecting upwardly into said channel;
a reference electrode spaced from said indicating electrode;
a chamber in said housing bridging said reference and indicating electrodes;
means for introducing an electrolyte into said chamber to cover said electrodes; and
wherein said channel is adapted to guide an open end of the capillary tube containing the liquid into engagement with the tip of the indicating electrode to displace the electrolyte therefrom whereupon an electrical property is established between the electrodes encompassing the electrolyte which is indicative of the chemical characteristic of the liquid.
1 Assignment
0 Petitions
Accused Products
Abstract
A method and apparatus for measuring a chemical characteristic of a liquid such as its hydrogen ion activity or pH value. A disposable cassette having a reference and indicating electrode therein utilizes the same solution to first calibrate the device and then as an electrolytic bridge from the liquid sample to the reference electrode. The solution has the properties of a buffered pH and also provides a stable electrochemical environment around the reference electrode. In one embodiment, a volume of a liquid sample is placed into a capillary tube and the open end of the tube is then placed over the indicating electrode immersed in the solution. The electrical potential between the indicating electrode and the spaced reference electrode in the electrolyte solution provides a measurement of the pH value of the liquid when compared to the calibration potential previously measured without the liquid sample contacting the indicating electrode.
27 Citations
19 Claims
-
1. A device for measuring chemical characteristics of a liquid, said device comprising:
-
a housing having upper and lower end surfaces; a longitudinally extending channel in said housing terminating at one end thereof at least upper surface of the housing and adapted to receive a capillary tube containing a sample of the liquid; an indicating electrode located about the longitudinal axis of said channel, with said indicating electrode having a tip projecting upwardly into said channel; a reference electrode spaced from said indicating electrode; a chamber in said housing bridging said reference and indicating electrodes; means for introducing an electrolyte into said chamber to cover said electrodes; and wherein said channel is adapted to guide an open end of the capillary tube containing the liquid into engagement with the tip of the indicating electrode to displace the electrolyte therefrom whereupon an electrical property is established between the electrodes encompassing the electrolyte which is indicative of the chemical characteristic of the liquid. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
-
11. Apparatus for measuring chemical characteristics of a liquid, said apparatus comprising:
-
a cassette containing spaced indicating and reference electrodes; means containing an electrolyte solution; and socket means for receiving said cassette, said socket means including means for making electrical connection to said electrodes and for causing said electrolyte solution to cover the electrodes when the cassette is inserted in the socket. - View Dependent Claims (12, 13, 14)
-
-
15. A device for measuring chemical characteristics of a liquid comprising a housing containing spaced indicating and reference electrodes bridged by a chamber;
- and a sealed member containing an electrolyte solution, said member being adapted to be broken to introduce the electrolyte into the chamber to cover the electrodes.
- View Dependent Claims (16, 17)
-
18. A machine for measuring electrochemical characteristics of a liquid, said machine being adapted to receive a cartridge containing spaced indicating and reference electrodes, said cartridge carrying a container filled with an electrolyte solution initially isolated from said electrodes, said machine comprising:
-
means for making electrical connection with said electrodes; means for urging said electrolye from said container to cover both of said electrodes with the electrolyte; means for measuring a first electrial property developed between the electrodes bridged by the electrolyte thereby establishing a calibration factor; and means for measuring a second electrical property developed between the electrodes when the indicating electrode comes into contact with the liquid to be measured whereby the chemical characteristics of the liquid can be calculated from the first and second electrical properties. - View Dependent Claims (19)
-
Specification