System and method for monitoring environmental conditions

• US 20090101728A1
• Filed: 11/17/2008
• Published: 04/23/2009
• Est. Priority Date: 12/24/2004
• Status: Active Grant

• Current Assignee: Copeland Cold Chain LP
• Original Assignee: PakSense Incorporated (Emerson Electric Company)
• Inventors: Jensen, Thomas
• Granted Patent: US 7,878,707 B2
• Time in Patent Office: Days
• US Class Current: 236/44.C
• CPC Class Codes: B65D 2201/00 Means or constructions for testing or controlling the contents
• CPC Class Codes: G01N 27/226 Construction of measuring vessels; Electrodes therefor
• CPC Class Codes: G01N 33/02 Food
• CPC Class Codes: H03M 1/50 with intermediate conversion to time interval H03M1/64 takes precedence
• CPC Class Codes: Y10T 29/53 Means to assemble or disassemble

Abstract

A system and method are disclosed for monitoring environmental conditions of a perishable product. The system includes an environmental sensor configured to sense one or more environmental conditions of the perishable product and an analog integrator in communication with the environmental sensor, the analog integrator being formed on a polymer substrate and including one or more tunable components. The system also includes a comparator in communication with the analog integrator and configured to change state when an output of the analog integrator reaches a selected threshold level, and a control module in communication with the comparator and the analog integrator. The control module is configured to control the operation of the analog integrator based on an output of the comparator.

Claims

1. A system comprising:

a humidity sensor coupled to a first analog integrator;

a temperature sensor coupled to a second analog integrator;

a first comparator coupled to the first analog integrator;

a second comparator coupled to the second analog integrator;

an analog-to-digital converter coupled to the humidity sensor and the temperature sensor; and

a control module coupled to the first and second analog integrators, the first and second comparators, and the analog-to-digital converter.

2. The system of claim 1, wherein the first and second analog integrators include one or more tunable components.

3. The system of claim 1, wherein the first and second analog integrators are fabricated on a polymer substrate.

4. The system of claim 1, wherein the control module comprises a microcontroller.

5. The system of claim 1, further comprising one or more indicator drivers coupled to the control module.

6. The system of claim 5, further comprising a display and/or audio emitter coupled to the indicator drivers.

7. The system of claim 1, further comprising a transceiver, real-time clock, and/or non-volatile memory coupled to the control module.

8. A method of tuning a system for monitoring environmental conditions of a perishable product, the method comprising:

fabricating a capacitor comprising a first capacitive plate formed on an upper surface of a polymer substrate and a second capacitive plate formed on a lower surface of the polymer substrate, the first and second capacitive plates comprising a capacitive plate material;

removing capacitive plate material while measuring the capacitance of the capacitor until a selected capacitance is reached; and

incorporating the capacitor into an analog integrator circuit configured to receive an input signal from an environmental sensor capable of monitoring one or more environmental conditions of the perishable product.

9. The method of claim 8, wherein removing capacitive plate material comprises using a robotic laser cutting device.

10. The method of claim 8, wherein the capacitive plate material comprises conductive material formed as layers of laminated, metallized polyester film.

11. The method of claim 10, wherein the polyester film comprises Mylar.

12. The method of claim 10, wherein the polyester film is metallized with aluminum, silver or gold.

13. The method of claim 8, wherein the polymer substrate comprises PET, polyamide or polypropylene.

14. The method of claim 8, further comprising incorporating the analog integrator circuit into a label, tag, package, or packaging material used in connection with the perishable product.

15. The method of claim 8, wherein the environmental sensor comprises a temperature sensor or humidity sensor.