# US 9,778,168 B2 · Coating monitor for evaluating the effectiveness of protective coatings

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 9,778,168 B2
- Document ID: US9778168B2
- Status: Granted
- Kind: B2
- Application number: 13/376,424
- Filed: 2010-06-08
- Published: 2012-04-05
- Granted: 2017-10-03
- Earliest claimed: 2009-06-10
- Assignees: ElectraWatch, Inc.
- Applicants: Guy D. Davis; Ryan C. Dunn; Robert A. Ross
- Inventors: Guy D. Davis; Ryan C. Dunn; Robert A. Ross
- Web page: https://patentgrep.com/patent/US9778168B2

## CPC

- G01N 17/02: Electrochemical measuring systems for weathering, corrosion or corrosion-protection measurement
- G01N 17/00: Investigating resistance of materials to the weather, to corrosion, or to light
- G01N 17/04: Corrosion probes
- G01N 27/00: Investigating or analysing materials by the use of electric, electrochemical, or magnetic means (G01N3/00 – G01N25/00 take precedence; measurement or testing of electric or magnetic variables or of electric or magnetic properties of materials G01R)
- G01N 27/02: by investigating impedance
- G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q)

## Abstract

The coating monitoring system is based on electrochemical impedance spectroscopy (EIS). The system consists of one or more compact and rugged mini-potentiostat modules coupled to one or more electrodes mounted on top of the paint coating of the structure being monitored. The electrodes and modules can be coated with a topcoat if desired. Alternatively, they may be mounted only temporarily to the structure for spot inspection. They periodically report to a laptop. Communications may be implemented using a wireless protocol. The units may be battery powered with an estimated battery lifetime of up to ten years, depending on the frequency of measurement and interrogation Alternative power supplies may be used to replace or supplement the battery to allow extended battery lifetime. Moisture, humidity, or other sensors may be incorporated into the coating monitor.

## Claims

### Claim 1

A bolt-mounted coating monitor comprising:
a bolt comprising a head and a threaded bolt body, said bolt body further comprising an electrically conductive material, and wherein said bolt head is provided with a recess and said bolt head is electrically isolated from said bolt body;
an application-specific-integrated-circuit comprising;
an ac voltage generator operating at a plurality of frequencies below 100 Hz;
a galvanometer;
a current conversion means capable of converting current measured by said galvanometer into electrochemical impedance measurements;
an input-output means capable of storing and transferring electrochemical impedance measurements generated by said current conversion means to an external storage device, and means to make an electrical connection to a substrate;
one or more electrodes electrically connected to a portion of said bolt head and electrically connected to said application-specific-integrated-circuit;
a power supply; wherein said application-specific-integrated-circuit and said power supply are mounted in said recess; and, wherein said means to make an electrical connection to a substrate is electrically connected to said threaded bolt body.

### Claim 2 (depends on 1)

The bolt-mounted coating monitor of claim 1 wherein said galvanometer measures both current magnitude and current phase.

### Claim 3 (depends on 1)

The bolt-mounted coating monitor of claim 1 further comprising moisture detecting means.

### Claim 4 (depends on 1)

The bolt-mounted coating monitor of claim 1 wherein said ac voltage generator operates at a plurality of frequencies below 10 Hz.

### Claim 5 (depends on 4)

The bolt-mounted coating monitor of claim 4 further comprising a washer placed between said portion of said bolt head and said electrode.

### Claim 6 (depends on 1)

The bolt-mounted coating monitor of claim 1 wherein the power supply further comprises an energy scavenging apparatus.

### Claim 7 (depends on 1)

The bolt-mounted coating monitor of claim 1 wherein the power supply further comprises a battery.

### Claim 8 (depends on 7)

The bolt-mounted coating monitor of claim 7 wherein the power supply further comprises an energy scavenging apparatus supplementing the battery.

### Claim 9 (depends on 8)

The bolt-mounted coating monitor of claim 8 wherein the energy scavenging apparatus further comprises a vibration energy scavenging apparatus.

### Claim 10 (depends on 1)

The bolt-mounted coating monitor of claim 1 wherein the power supply further comprises a solar cell apparatus.