Concentration monitor

• US 8,012,421 B2
• Filed: 06/24/2003
• Issued: 09/06/2011
• Est. Priority Date: 06/24/2003
• Status: Active Grant

• Current Assignee: Ecolab USA Incorporated (Ecolab, Inc.)
• Original Assignee: Ecolab, Inc.
• Inventors: Van Dao, Quang, Mehus, Richard J., Hodge, Charles A.
• Primary Examiner(s): SIEFKE, SAMUEL P
• Application Number:
  US10/602,384
• Publication Number:
  US 20040265174A1
• Time in Patent Office: 2,996 Days
• Field of Search: 73/10.2, 73/530.1, 73/10.1, 422/82.01, 422/82.02, 422/50, 422/68.1, 436/43, 436/149, 436/150
• US Class Current: 422/82.02
• CPC Class Codes: A47L 15/0055 Metering or indication of used products, e.g. type or quantity of detergent, rinse aid or salt; for measuring or controlling the product concentration
• CPC Class Codes: A47L 15/4297 Arrangements for detecting or measuring the condition of the washing water, e.g. turbidity
• CPC Class Codes: A47L 2401/12 Water temperature
• CPC Class Codes: A47L 2401/30 Variation of electrical, magnetical or optical quantities
• CPC Class Codes: A47L 2501/26 Indication or alarm to the controlling device or to the user
• CPC Class Codes: D06F 2103/16 Washing liquid temperature
• CPC Class Codes: D06F 2103/22 Content of detergent or additives
• CPC Class Codes: D06F 2105/42 Detergent or additive supply
• CPC Class Codes: D06F 2105/58 Indications or alarms to the control system or to the user
• CPC Class Codes: D06F 2105/60 Audible signals
• CPC Class Codes: D06F 34/22 Condition of the washing liquid, e.g. turbidity
• CPC Class Codes: G01N 27/06 of a liquid involving electrolysis G01N27/26
• CPC Class Codes: Y10T 436/25 including sample preparation

Abstract

A concentration monitor for monitoring a concentration of a plurality of use solutions, each of the plurality of use solutions being, at least, a concentrate in a diluent, each of the plurality of use solutions having a resistivity which varies as a function of both temperature and an amount of the concentrate contained in a given amount of the diluent. A resistivity probe is adapted for use with at least one of the plurality of use solutions for taking a measurement related to the resistivity of the at least one of the plurality of use solutions. A temperature sensor is adapted for use with the at least one of the plurality of use solutions for taking a measurement related to the temperature of the at least one of the plurality of use solutions. A controller calculates the concentration of the at least one of the plurality of the use solutions based upon a predetermined algorithm using the resistivity and the temperature for the particular one of the at least one of the plurality of use solutions, the algorithm being based upon knowledge of the at least one of the plurality of use solutions being measured.

Claims

1. A concentration monitor comprising:

a resistivity probe that measures resistivity of a selected one of a plurality of use solutions;

a temperature sensor that measures a temperature of the selected use solution;

a memory that stores a plurality of predetermined algorithms, each associated with a different one of a plurality of product classifications; and

a controller that calculates a concentration of a product in the selected use solution based on the resistivity, the temperature and one of the plurality of the predetermined algorithms associated with a product classification of the product in the selected use solution.

2. The concentration monitor of claim 1 wherein the controller stores information concerning identification of the selected use solution.

3. The concentration monitor of claim 2 wherein the controller receives user selected information concerning identification of the selected use solution a user controllable setting.

4. The concentration monitor of claim 1, further including a user interface that reports the concentration to a user.

5. The concentration monitor of claim 1 wherein the algorithm is linear.

6. The concentration monitor of claim 1 wherein the controller performs a function based upon the concentration.

7. The concentration monitor of claim 1 wherein the controller further controls addition of concentrate of the product to the use solution when the concentration falls below a predetermined level.

8. The concentration monitor of claim 1 wherein the algorithm is determined based on empirical measurements of use solutions having known product concentrations.

9. The concentration monitor of claim 1 wherein the algorithm is determined based on empirical measurements of the conductivity of use solutions having known product concentrations.

10. The concentration monitor of claim 8 wherein the empirical measurements are taken over a range of temperatures.

11. The concentration monitor of claim 8 wherein the algorithm includes an equation fit to the empirical measurements.

12. The concentration monitor of claim 8 wherein the algorithm includes a lookup table corresponding to the empirical measurements.

13. The concentration monitor of claim 1 wherein the product classification is user selectable.