HAND HELD MOISTURE METER IN-FIELD CALIBRATION

• US 20200132524A1
• Filed: 10/15/2019
• Published: 04/30/2020
• Est. Priority Date: 10/31/2018
• Status: Active Grant

• Current Assignee: Wagner Electronic Products, Inc.
• Original Assignee: Wagner Electronic Products, Inc.
• Inventors: Duncan, Timothy
• Granted Patent: US 11,131,569 B2
• Time in Patent Office: Days
• CPC Class Codes: G01D 18/006 Intermittent recalibration
• CPC Class Codes: G01N 27/223 for determining moisture content, e.g. humidity rain detectors on vehicle windows B60S1/0825
• CPC Class Codes: G01N 33/46 Wood

Abstract

Methods and apparatus are disclosed for calibration determinations for handheld moisture meters in the field. A calibration reference stand emulates a sample with an equivalent moisture content, allowing rapid determination whether a moisture meter is out of calibration, or determination of a new calibration value. The calibration reference stand includes an electromagnetic load, which can be formed of a metal sheet or high dielectric constant material, supported on a platform, and mechanical fixturing for reproducible positioning of a moisture meter on the stand. Associated methods and variations are disclosed.

Claims

1. A computer-implemented method comprising:

receiving an input at a moisture meter to trigger a calibration determination;

obtaining a measurement of a calibration reference stand with the moisture meter;

analyzing the measurement with reference to a predetermined calibration value of the calibration reference stand and based on the moisture meter being positioned on a sensor pad of the calibration reference stand; and

making the calibration determination based on the analyzing.

2. The computer-implemented method of claim 1, wherein the calibration determination is that the moisture meter is out of calibration.

3. The computer-implemented method of claim 1, wherein the calibration determination is a new calibration value of the moisture meter.

4. The computer-implemented method of claim 3, further comprising storing the new calibration value in non-volatile memory of the moisture meter.

5. The computer-implemented method of claim 3, wherein the measurement is a first measurement, and further comprising:

responsive to the moisture meter being positioned in a second position spatially apart from any electromagnetic load, obtaining a second measurement with the moisture meter; and

determining a second calibration value of the moisture meter.

6. The computer-implemented method of claim 5, further comprising:

based on the new and second calibration values, determining a plurality of updated calibration values covering a measurement range of the moisture meter; and

storing the plurality of updated calibration values in non-volatile memory of the moisture meter.

7. The computer-implemented method of claim 5, further comprising prompting a user to position the moisture meter in the second position.

8. One or more computer-readable media storing instructions which, when executed by one or more processors, cause the one or more processors to perform the computer-implemented method of claim 1.

9. A system comprising:

one or more computer-readable media storing instructions which, when executed by one or more processors, cause the one or more processors to perform the computer-implemented method of claim 1, wherein the one or more computer-readable media are integrated within the moisture meter;

the moisture meter, wherein the moisture meter further comprises;

a sensor;

the one or more processors, with memory coupled thereto, situated within the moisture meter and configured to execute the instructions; and

writable non-volatile storage storing the predetermined calibration value; and

the calibration reference stand.

10. A calibration reference stand, comprising:

a platform;

a sensor pad and a electromagnetic load supported by the platform;

wherein the sensor pad defines a location at which a sensor of a moisture meter can be received, and the electromagnetic load is positioned spatially apart from the location; and

wherein the calibration reference stand is configured to present the electromagnetic load to the sensor as equivalent to a predetermined moisture content value, when the sensor is positioned at the location.

11. The calibration reference stand of claim 10, further comprising a plurality of legs extending downwardly from the platform.

12. The calibration reference stand of claim 10, wherein the electromagnetic load is a metal sheet.

13. The calibration reference stand of claim 10, wherein the electromagnetic load extends spatially beyond the sensor in at least one direction when the sensor is positioned at the location.

14. The calibration reference stand of claim 10, wherein the platform comprises an insulator, at least part of which is situated between the electromagnetic load and the location.

15. The calibration reference stand of claim 10, wherein the calibration reference stand and the moisture meter are individually matched to each other.

16. The calibration reference stand of claim 10, wherein the location is defined by one or more structural features of the sensor pad that facilitate reproducible positioning of the sensor at the location.

17. The calibration reference stand of claim 16, wherein the one or more structural features comprise a rectangular relief at a surface of the sensor pad.

18. A method comprising:

calibrating a moisture meter with a traceable standard;

providing a calibration reference stand, distinct from the traceable standard, for the moisture meter;

determining a reference value for a combination of the moisture meter and the calibration reference stand; and

storing the reference value in non-volatile memory.

19. The method of claim 18, wherein the non-volatile memory is external to the moisture meter and the reference value is accessible from the moisture meter over a network.

20. The method of claim 18, further comprising:

determining a test value for the combination of the moisture meter and the calibration reference stand;

comparing the test value and the reference value; and

based on the comparing, making a determination regarding calibration of the moisture meter.