Holiday Detectors: Your Guide to the Top Pinhole Testers for Rent & Sale [New for 2024]

A holiday detector is a tool inspectors and members of maintenance teams use to identify flaws or defects in protective coatings, known as “holidays.”

These defects, which include pinholes, porosity, and thin areas, can compromise the integrity of the coating on industrial assets, leading to issues like corrosion or structural damage over time. Holiday detectors help ensure that the applied coating is free from imperfections and is capable of providing long-term protection to critical infrastructure.

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Holiday detectors are known by several names in the coating inspection and corrosion protection industry. Some common alternative terms for holiday detectors include:

• Holiday tester
• Pinhole detector
• Porosity detector
• Continuity tester
• Spark tester
• Jeep meter

 

Industries that use protective coatings—such as oil and gas pipelines, marine vessels, and industrial tanks—rely on holiday testers to detect microscopic flaws before they become serious problems. Identifying and correcting coating deficiencies at an early stage helps preserve the structural integrity of assets and avoid costly repairs or system failures down the line. By using a holiday tester, inspectors can verify that coatings are applied properly and meet the necessary standards for corrosion prevention.

Whether in large-scale infrastructure projects or smaller applications, holiday testers are critical tools in safeguarding materials and ensuring the long-term performance of protective coatings.

In this guide to holiday detectors we’ll share the top holiday detectors on the market, how holiday testers works, and a lot more.

Holiday Detector Rental and Sales [New for 2024]

Want to buy or rent a holiday detector? Here are the top options on the market.

1. Tinker & Rasor AP/W

The Tinker & Rasor AP/W is a high-quality holiday detector designed for use in a variety of industrial applications where protective coatings need to be inspected for flaws such as pinholes, cracks, or voids. This model is widely recognized for its durability and ease of use, making it ideal for pipeline and storage tank inspections.

• Type. High-voltage holiday detector
• Voltage range. Adjustable from 800 to 35,000 volts
• Application. Suitable for coatings of varying thicknesses on metal surfaces
• Features. Portable, battery-operated, with a rugged design for field use
• Durability. Built to withstand harsh environments and tough inspection conditions

Learn more about the Tinker & Rasor AP/W.

2. PCWI DC30

The PCWI DC30 is a reliable high-voltage holiday detector that is widely used for detecting coating flaws, such as pinholes or cracks, on metal surfaces. It is known for its precision and ease of use, making it suitable for various industrial applications, including pipeline and tank inspections.

• Type. High-voltage holiday detector
• Voltage range. Adjustable from 1 to 30 kilovolts
• Application. Suitable for coatings up to 20mm thickness
• Features. Ergonomic design, lightweight, and user-friendly interface
• Power source. Battery-operated, with long-lasting battery life

Learn more about the PCWI DC30.

What Is a Holiday Detector?

A holiday detector is a specialized testing device used to detect flaws, pinholes, or thin spots in non-conductive protective coatings applied to metal surfaces.

These flaws, also known as “holidays,” can compromise the coating’s ability to prevent corrosion, leading to costly structural damage over time. By identifying these imperfections early, industries can ensure that their assets, such as pipelines, storage tanks, and marine vessels, are properly protected against corrosion and other environmental factors.

Known by several different names, these devices all serve the same primary function of detecting flaws, discontinuities, or “holidays” in protective coatings. The different names often reflect slight variations in the technology or specific application:

• Pinhole detector emphasizes the ability to find very small defects.
• Porosity detector focuses on identifying areas where the coating is porous or permeable.
• Continuity tester refers to the device’s function of checking for continuous, unbroken coating coverage.
• Spark tester describes the visual spark or audible signal produced when a flaw is detected.
• Jeep meter is an informal term derived from the sound some detectors make when identifying a holiday.

Regardless of the name used, these instruments are crucial tools in ensuring the integrity of protective coatings on various substrates, including metal pipelines, tanks, and concrete structures

How Does a Holiday Detector Work?

Holiday detectors work by using electrical currents to identify defects in the coating.

There are two main types of holiday detectors: low-voltage and high-voltage detectors.

• Low-voltage detectors are typically used for thinner coatings.
• High-voltage detectors, also known as spark testers, are used for thicker coatings.

In both cases, the detector passes an electric charge over the coated surface. When it encounters a flaw, the current travels through the defect and into the conductive material underneath, triggering an alarm or signal to alert the inspector.

Why Are Holiday Detectors Important?

Industries such as oil and gas, infrastructure, and construction rely on holiday detectors to ensure the quality of protective coatings.

These detectors, which can also function as pinhole detectors or porosity detectors, play a critical role in maintaining the integrity of pipelines, tanks, and other structures exposed to harsh environments.

By detecting flaws in coatings before they lead to corrosion, holiday detectors help prevent environmental hazards, ensure operational safety, and reduce maintenance costs.

What Is a Holiday Detector Used For?

Holiday detectors are indispensable in industries where protective coatings are applied to metal surfaces to prevent corrosion and structural damage.

These devices ensure that coatings are free from pinholes, porosity, and other defects, safeguarding the material underneath.

The top use cases for holiday detectors include:

1. Pipeline Inspections

In the oil and gas industry, pipelines are constantly exposed to harsh environments.

A holiday tester is critical during pipeline inspections to ensure the integrity of protective coatings applied to both underground and above-ground pipelines. Even the smallest pinhole or imperfection in the coating can lead to corrosion, leaks, or hazardous spills.

Holiday detectors are used to check the coating quality on new pipelines as well as during routine maintenance to prevent long-term damage.

2. Protective Coating Quality Checks

Industries that rely on protective coatings, such as marine and offshore platforms, storage tanks, and chemical processing facilities, use pinhole detectors and porosity detectors to ensure that the coatings are applied correctly.

Coatings are often applied to surfaces that come into contact with water, chemicals, or other corrosive substances.

A holiday detector helps verify that the coatings are free of any imperfections, ensuring longevity and corrosion resistance.

3. Corrosion Prevention

Corrosion is a significant concern for industries like construction, infrastructure, and power generation.

Holiday detectors are used as part of a preventative maintenance strategy to identify and repair any flaws in the coating that could lead to corrosion over time. By detecting and addressing these defects early, industries can reduce repair costs and extend the lifespan of their equipment and infrastructure.

How the Holiday Test Procedure Works

The holiday test is crucial for detecting defects in protective coatings, such as pinholes or cracks, that can compromise corrosion protection.

The process of holiday detection varies depending on the type of holiday detector used, whether it’s a low-voltage or high-voltage tester, and the thickness of the coating being inspected.

Here’s a step-by-step guide to the holiday testing procedure:

1. Surface Preparation

Before conducting the holiday test, the surface must be clean and dry.

Any debris, dirt, or contaminants can affect the accuracy of the test. For conductive coatings, ensure the substrate is properly grounded.

2. Choosing the Appropriate Holiday Tester

The choice of holiday tester depends on the thickness and type of coating applied:

• Low-voltage holiday detectors (continuity testers). These devices are used for detecting flaws in thin coatings, typically less than 500 microns thick. They operate by running a low voltage across the coating and detecting breaks in continuity.
• High-voltage holiday detectors (spark testers). These are used for thicker coatings, usually above 500 microns. High-voltage spark testers generate an electrical arc that jumps through the coating at defect points, creating a spark that indicates a flaw.

3. Conducting the Test

The holiday tester is moved across the coated surface, either manually or with automated equipment. The process varies based on the type of tester:

• Low-voltage holiday detector. A sponge or wetting agent is used to apply the voltage evenly. When the continuity is broken by a defect, the tester emits an alarm or signal.
• High-voltage holiday detector. The high voltage passes through a brush or electrode. When it encounters a defect, the electrical charge jumps through the coating, resulting in a visible spark or audible alert.

4. Marking and Repairing Defects

Each detected holiday (flaw) is marked for further inspection and repair. After repairs are made, the surface is typically re-tested to ensure all defects have been addressed.

5. Post-Test Evaluation

Once all holidays have been identified and repaired, a final inspection ensures that the coating is intact and provides complete corrosion protection.

Types of Holiday Detectors

Holiday detectors are available in different types to suit various coating thicknesses and application environments.

The two primary categories are low-voltage and high-voltage holiday detectors. Each type is designed for specific use cases, depending on the nature of the coating and the sensitivity of the inspection required.

Below is an overview of the key differences between low-voltage and high-voltage holiday detectors, as well as when each should be used.

1. Low-Voltage Holiday Detectors

Low-voltage holiday detectors, also known as continuity testers, are designed for testing thin coatings (typically less than 500 microns thick). They work by applying a low voltage across the surface of the coating and identifying breaks in the coating’s continuity.

• Best for: Thin coatings, such as those found on storage tanks, pipelines, or other metal structures.
• How it works: A wet sponge or similar medium is used to evenly distribute the electrical charge over the surface. If a flaw is present, the current will pass through the break in the coating and trigger an alarm.
• Advantages: Ideal for detecting very small defects in thin coatings. These detectors are also more affordable and easier to operate.

2. High-Voltage Holiday Detectors

High-voltage holiday detectors, sometimes referred to as spark testers or jeep meters, are designed for thicker coatings, generally above 500 microns. These detectors operate by generating a high-voltage spark that can jump across any defects in the coating.

• Best for: Thicker coatings, typically found in industries like oil and gas pipeline protection or large infrastructure projects.
• How it works: The high-voltage current is applied through a brush or electrode. When it encounters a holiday, the current will arc through the defect, creating a visible spark or audible alarm.
• Advantages: Capable of detecting deeper and more substantial flaws in thicker coatings. Essential for industries requiring strong, corrosion-resistant coatings.

How Do You Choose?

Choosing between low-voltage and high-voltage holiday testers depends on the type of coating being inspected and the specific application.

Low-voltage detectors are sufficient for thin coatings, while high-voltage detectors are essential for ensuring the integrity of thicker protective layers.

6 Benefits of Using Holiday Detectors for Coating Inspections

Here are the six main advantages inspectors get from using holiday testers in their work.

1. Early Detection of Flaws

Holiday detectors, also known as pinhole or porosity detectors, help identify defects in coatings at an early stage. Small flaws such as pinholes, cracks, or areas of porosity can go unnoticed to the naked eye, but these detectors ensure that any discontinuities are located before they lead to more severe issues.

2. Prevention of Corrosion

Detecting small defects in coatings is crucial in preventing corrosion. If left unchecked, these flaws expose the underlying metal to moisture and air, which can cause rust and ultimately weaken the structure.

A holiday tester ensures that all areas are thoroughly inspected, reducing the chances of corrosion-related failures.

3. Increased Durability of Protective Coatings

By identifying small imperfections, holiday testers help ensure the integrity of protective coatings. This leads to increased durability of the coating, improving the lifespan of assets and reducing the need for costly repairs or reapplications in the future.

4. Compliance with Industry Standards

Many industries, such as oil and gas, infrastructure, and manufacturing, require coatings to be inspected with porosity detectors to meet strict quality and safety standards.

Using holiday detectors ensures compliance with these regulations, which helps avoid fines, operational downtime, and potential safety hazards.

5. Cost-Effective Maintenance

Regularly inspecting coatings with holiday detectors can help identify small issues before they escalate into larger problems. This proactive approach reduces long-term maintenance costs and prevents expensive, unplanned repairs.

6. Enhanced Structural Integrity

By ensuring that protective coatings are free of defects, holiday detectors contribute to maintaining the structural integrity of critical components, such as pipelines, tanks, and infrastructure elements. This adds to the overall safety and longevity of assets.

Maintaining and Calibrating Holiday Detectors

It’s critical to perform regular maintenance and calibration on holiday detectors to ensure their accuracy and effectiveness in detecting flaws in protective coatings.

Whether using a low-voltage holiday detector, a high-voltage spark tester, or a continuity tester, keeping the device in optimal condition will extend its lifespan and improve inspection results.

Holiday Tester Calibration

Calibrating a holiday detector involves verifying that the device delivers the correct voltage according to the coating thickness being tested.

Devices like the jeep meter are commonly used for this purpose, ensuring that the detector is correctly calibrated before use. Calibration should be performed regularly, especially after prolonged storage or frequent use, to maintain the accuracy of the readings.

• Use of jeep meter. A jeep meter measures the output voltage of the holiday detector to ensure it aligns with the required test voltage for the coating. This prevents under-testing or over-testing, which could either miss flaws or damage the coating.
• Routine calibration. Perform calibration checks before each inspection, particularly when working with varied coating thicknesses.

Holiday Tester Maintenance

Maintaining a holiday detector involves routine inspections of the device components, including the probe, leads, and battery. Regular cleaning and replacement of worn-out parts help prevent malfunction and ensure consistent performance.

• Battery checks. Inspect the battery regularly to ensure it holds sufficient charge, especially for high-voltage detectors, as low battery levels can reduce test accuracy.
• Probe maintenance. Clean the probe after each use to remove any residue that could affect conductivity.
• Lead inspection. Check the continuity tester leads for wear or damage to prevent inaccurate readings during testing.

By adhering to regular maintenance and calibration schedules, you can ensure that your holiday detector continues to operate effectively, reducing the risk of coating failures and increasing the safety and durability of your assets.

Holiday Detector FAQ

What is a holiday detector?

A holiday detector is a device used to locate and identify defects or flaws in protective coatings, such as pinholes, cracks, or voids, that could lead to corrosion. It is commonly used in industries like oil and gas, where maintaining coating integrity is crucial for preventing damage and maintaining structural safety.

What is a holiday detector used for?

A holiday detector is primarily used for inspecting coatings on pipelines, tanks, and other metal structures to detect any discontinuities or imperfections that may allow corrosion to occur. It ensures the effectiveness of protective coatings by identifying flaws that are invisible to the naked eye.

What is the holiday test procedure?

The holiday test procedure involves passing a detector, either low-voltage or high-voltage, over the coated surface. When a flaw or pinhole is detected, the detector emits a spark or signal to alert the operator of the imperfection. The test ensures that coatings are fully intact and able to provide the necessary protection.

Why is it called the holiday test?

The term “holiday” in this context refers to a gap or defect in a protective coating. In the oil and gas industry, “holiday” has historically meant a missed area or flaw in the application of coatings. The holiday test is designed to detect these missed areas or defects.

How does a holiday detector locate coating defects?

Holiday detectors locate defects in coatings by applying either a low or high voltage to the surface of the coating. If there is a flaw or pinhole in the coating, the detector creates an electrical connection, signaling the defect’s location. This allows inspectors to identify and repair these flaws before the coating system is compromised.

What is the difference between low-voltage and high-voltage holiday detectors?

Low-voltage holiday detectors are typically used for thin coatings and can detect small defects using a gentle electrical current. High-voltage holiday detectors are designed for thicker coatings and use a stronger current to find deeper flaws. The choice of detector depends on the thickness and type of coating being inspected.

Why are holiday detectors important for corrosion prevention?

Holiday detectors are essential for ensuring the long-term durability of protective coatings. By identifying defects early, they help prevent corrosion, which could lead to costly repairs, equipment failure, or safety hazards in industries like oil and gas, construction, and infrastructure.

What are some common alternatives to holiday detectors?

Alternatives to holiday detectors include visual inspections and ultrasound testing. However, holiday detectors are considered more reliable and effective for detecting coating flaws, especially in industrial applications where accuracy is critical.