Automated self-calibrating water quality monitoring sensor housing assembly

• US 6,936,156 B2
• Filed: 08/30/2001
• Issued: 08/30/2005
• Est. Priority Date: 08/30/2001
• Status: Expired due to Fees

• Current Assignee: The United States of America as represented by the Secretary of the Interior
• Original Assignee: The United States Of America As Represented By The Secretary Of The Department Of The Interior
• Inventors: Granato, Gregory E., Smith, Kirk P.
• Primary Examiner(s): NOGUEROLA, ALEXANDER STEPHAN
• Application Number:
  US09/881,243
• Publication Number:
  US 20030042149A1
• Time in Patent Office: 1,461 Days
• Field of Search: 205/778.5, 205/781.5, 205/789, 205/775, 204/409, 204/411, 204/412, 204/416, 204/418, 204/419, 204/401, 422/50, 422/62, 422/82.01, 422/82.03, 422/82.02
• US Class Current: 205/775
• CPC Class Codes: G01N 27/4163 checking the operation of, or calibrating, the measuring apparatus G01N27/3274, G01N27/4175 and G01N33/0006 take precedence
• CPC Class Codes: G01N 33/18 Water

Abstract

An automated self-calibrating water quality monitoring sensor housing assembly includes a number of ion-selective electrodes combined in a single flow train to provide for the multi constituent analysis of a number of samples without direct intervention by a human operator. An operator can enter the laboratory, connect sample bottles to an intake manifold, activate the device, and download data once the analysis is complete. With the exception of periodic probe maintenance, the system is designed to be self-calibrating and self cleaning.

Claims

1. An automated process for monitoring water quality comprising:

providing a system for monitoring water quality, the system comprising a plurality of ion-selective electrodes and probes combined in a single flow train for multi-constituent analysis of a plurality of samples and a recirculation pump for optionally recirculating samples and reagents;

rinsing and gas purging the system for monitoring water quality;

self-testing and calibrating the probes;

recording calibration data;

rinsing and gas purging the system;

optionally notifying an operator of the system if the operational parameters of the probes do not meet prespecified criteria;

introducing sample to be tested into the system;

optionally adding buffer or ionic-strength adjusting solution to the probes;

monitoring water quality by measuring the analytes in the sample with the probes;

recording the measurements;

optionally conducting a second measuring step adding appropriate solution to dilute the sample in the probes or create a spike, measuring the analytes to be determined in the sample, and recording the water-quality measurement;

optionally recalibrating the system after a number of samples are measured to detect drift of probe calibration parameters; and

producing or transmitting a computer file to record the results of the monitoring process.

2. The process according to claim 1 wherein once the water quality conditions are monitored, further notifying an operator of the results obtained for the water quality conditions monitored.

3. The process according to claim 2 wherein the operator is notified using a voice modem or electronic mail.

4. The process according to claim 1 wherein the status of the system is monitored based upon signals indicating the existence of at a a least one error condition.

5. The process according to claim 4 wherein the error conditions are selected form the group consisting of low sample level, insufficient power supply, malfunctioning probes, and at a a least one measurement lying outside a predetermined range.

6. The process according to claim 4 wherein, once an error condition is detected, the process is terminated and a warning signal is automatically transmitted to an operator.

7. The process according to claim 1 wherein the probes are configured in a single flow train.

8. An automated self-calibrating water quality monitoring system housing assembly comprising:

a plurality of ion-selective electrodes and probes combined in a single flow train for multi-constituent analysis of a plurality of samples;

inlet ports for introducing purified gases into the system to gas purge the system and to clean the system between samples;

reservoirs for solutions used in water quality monitoring;

a pump for introducing said solutions from the pulsating pressure of the order of 50 to 450 mbar to the reservoirs through ports to the sample containers;

sample containers connected to a sample pump for the sample to be sent through the flow train for analysis;

a recirculation pump for optionally recirculating samples and reagents; and

an electronic control module for controlling the system and collecting data obtained from the electrodes and the probes.

9. The system according to claim 8, further including a heat pump for temperature control.

10. The system according to claim 8 wherein the probes are selected from the group consisting of temperature, conductance, dissolved oxygen content, turbidity, and pH.

11. The system according to claim 8, wherein the ion-selective electrodes are selective for ions selected from the group consisting of ammonium, chloride, sodium, calcium, lead, cadmium, copper, nitrate, and nitrite.

12. The system according to claim 8 wherein the flow train is configured for repeated measurement in a recirculation loop.

13. The system according to claim 8 wherein the solutions are selected from the group consisting of deionized water, ionic strength adjustment solutions, and known volumes of standard solutions.