Inspection Tools: A Guide to the Tools Inspectors Use in Their Daily Work
Inspection tools help inspectors collect the data they need to ensure the proper maintenance of the assets they're inspecting—Read this guide for an overview of the different types of inspection tools they use.
Inspection tools help inspectors to collect data.
This data could be visual, thermal, or related to thickness measurements. The specific type of data needed for an inspection will be determined by the inspection requirements, which will in turn determine the types of inspection tools needed for the job.
After collecting data, inspectors examine it to understand the condition and maintenance status of the thing they are inspecting.
Whether it’s a huge industrial boiler or a home HVAC unit, the basic idea is the same:
- Inspectors collect data using inspection tools
- Inspectors analyze that data using methods specific to the industry in which they are working
- Inspectors and/or maintenance personnel make a maintenance determination based on that analysis
Although the overall idea is fairly straightforward, the types of inspection tools that inspectors use can vary greatly.
That being said, they can generally be organized by the types of data they’re used to inspect.
It’s worth noting that, in the case of robotics solutions, the manner of data collection (i.e., aerial or ground-based) is used to organize the tools instead of the specific type of data the tools capture. That is, drones and ground-based robots can sometimes be equipped with different sensors, which means that the same inspection tool can be used to capture different types of data.
The primary types of inspection tools include:
- Cameras and other visual data collection devices
- Other NDT sensors and testing methods
- Robots—Ground-based solutions
- Measuring devices
Inspection Tools vs. Inspection Equipment
For the purposes of this article, inspection tools are the actual tools and instruments inspectors use to collect data.
This could be a thickness measuring sensor that helps inspectors evaluate the thickness of a wall inside a coke drum, or it could be a drone with a camera that helps inspectors enter a boiler in order to collect visual data on its condition from a remote location.
Inspection equipment, on the other hand, is anything that helps inspectors get access to data or that simply supports their work as they collect data.
This could be the toolbelt an inspector wears, the scaffolding inspectors stand on to manually collect visual data with the naked eye, or the ropes inspectors use to climb or rapel inside an asset in order to collect the data they need.
Now let’s take a closer look at each type of inspection tool.
Cameras and other visual data collection devices
In any field, visual data is one of the most common types that inspectors need to collect.
And of course, cameras are the go-to inspection tool for collecting visual data, but not all cameras will be useful for a given inspection.
As noted above, the primary criteria to use when choosing an inspection tool for collecting visual data is the data requirement. If the camera you’re considering can collect the data you need at a quality you can use to execute your inspection, then it’s the right tool for the job.
Here are some common types of visual data collection tools:
- Digital cameras. Digital cameras vary greatly in terms of quality and cost, so it’s important to know exactly how precise you need your images to be. Other factors like the ability to work in low lighting conditions or the need for high quality color may also impact your decision-making when choosing a good digital camera as an inspection tool.
- Borescopes. A borescope is a visual inspection tool that consists of a tube with an eyepiece at one end and a lens at the other. Borescopes allow inspectors to see areas that are otherwise inaccessible (see picture below).
- Video and digital microscopes. Video and digital microscopes magnify images using digital technology. These types of microscopes allow inspectors to get up-close visual data, and typically come with high-powered lenses that render clear images, even of very small objects.
- Videoscopes. Videoscopes give inspectors a way to see inside small cavities and other areas remotely. Their camera is embedded in the tip of the scope and uses CCD technology along with focusable lens assembly to relay images.
- CCTV. Closed Circuit Television is often used for inspecting pipes, specifically for sewer inspections, because it allows inspectors to see inside pipes and drains remotely.
A borescope being used to inspect a car engine
Other NDT sensors and testing methods
Although visual data is the most common type of data inspectors need to collect, there are lots of other types that might be needed to meet the requirements of a given inspection.
Each type of data an inspectors needs will require a different inspection tool with a sensor made for collecting that data, or an NDT (Non-Destructive Testing) method that can collect the data required.
Ropes and Drones Case Study
A good example of inspectors using various types of tools and NDT methods to collect all the data they need can be seen in a recent inspection conducted by Premium Inspection & Testing, an inspection service provider based in Baton Rouge, Louisiana.
Inspectors from Premium needed to conduct a coke drum inspection without building scaffolding. To do this, they used a unique combination of drones and rope access so that they could leverage all of the inspection tools required for the job.
Photo credit: Premium Inspection & Testing
Here are the steps the Premium team followed to complete the inspection:
1. Visual data collected by drone
Using Flyability’s Elios 2 drone, inspectors collected visual data inside the coker to make sure it was clean and to identify potential areas where inspectors might want to focus their attention (see the next section for more information on the Elios 2).
2. Corrosion, pitting, and other data collected by rope access
Using rope access, inspectors performed other types of data collection inside the coke drum, including:
- Creaform 3D scanning to determine the extent of surface pitting and corrosion
- Phased array testing to test the integrity of the weld seams
- Liquid penetrant testing to identify defects in the seams and shell
This mission highlights the ways that various sensors might be used during a single inspection in order to collect all the data needed to satisfy an inspection’s requirements.
It’s worth noting that this approach not only allowed inspectors to collect all the data they needed without using scaffolding, it also helped them save their client $250,000 in the process.
NDT Sensors and Testing Methods
Here are some examples of data inspectors might need which would require specific sensors or NDT testing methods:
- Thermal data. Thermal data is collected with a thermal or infrared sensor. It can be used to help inspectors determine where heat is leaking out of a structure or where there might be an excess of heat inside a closed system.
- Ultrasonic data. Ultrasonic data is collected with an ultrasonic sensor. This type of NDT testing uses sound waves to detect defects or imperfections on the surface of a material created.
- Radiography data. Radiography testing is the act of using gamma- or X-radiation on materials to identify imperfections in a surface.
- Eddy current data. Eddy current testing is a type of electromagnetic testing that uses measurements of the strength of electrical currents (also called eddy currents) in a magnetic field surrounding a material to locate defects in the material or make other inspection-related determinations about it.
See our in-depth guide to Non-Destructive Testing for more information on NDT methods and data collection.
Over the last several years, inspectors working in industrial scenarios have started using robots to collect inspection data remotely.
Any tool that allows an inspector to collect data remotely falls under the umbrella term Remote Visual Inspection (RVI), and drones are quickly becoming one of the most common types of RVI tools.
Inspectors typically use drones to collect visual data, but some drones can also collect thermal data or even be outfitted with unique sensors that allow them to collect other kinds of data. As drone technology develops, the ability to use different kinds of sensors with them to enable new types of data collection will only continue to grow.
Why use RVI tools?
Here are the three biggest benefits to using a robot like a drone to collect inspection data:
- Safety. By using a drone or other robot to collect data you can reduce the need for a person to place themselves in hazardous situations to collect inspection data, such as standing on scaffolding, entering a confined space, or using rope access. Learn more about how indoor drones help companies improve safety.
- Savings. Drones can reduce the cost of an inspection significantly, sometimes by as much as 90% or more. Savings are primarily realized from avoiding the need for temporary structures, like scaffolding, used in manual data collection, and also in reduced work hours and downtimes. Learn more about how indoor drones help companies save money.
- Reduced downtimes. Because drones can significantly speed up the inspection process by avoiding the need for building and taking down scaffolding and the speed of data collection, using them can result in significant downtime reductions.
Indoor vs. outdoor drones
Indoor drones are inspection tools made for operating in confined spaces.
Flyability’s Elios 2 (shown above) is an indoor drone that sits in a cage, allowing it to collide while operating in confined spaces and continue flying. This kind of design was created with indoor inspection scenarios in mind.
Boilers, pressure vessels, and tanks are all examples of assets commonly inspected with an indoor drone, but there are many other types of assets that require a drone like this—check out our case studies to see all the different industries benefiting from the use of indoor drones.
Outdoor drones, on the other hand, are made for collecting inspection data outdoors, and don’t come with the same kind of cage or collision tolerance that an indoor drone has.
DJI's Matrice 300, an outdoor drone commonly used in inspections
Another type of RVI tool that inspectors use to collect inspection data are ground-based robotics solutions—that is, robots.
Ground-based robots can provide the same kinds of benefits that drones do for inspectors, helping them increase savings while improving safety during inspections.
There are several different types of robots out there made specifically for inspection data collection—here are just a few examples:
The Inuktun MaggHD is a miniature magnetic crawler used for remote visual inspection (RVI) in lieu of hazardous confined space entry (CSE) or working at heights.
Deep Trekker DT320
The Deep Trekker DT320 is a mini pipe crawler made for inspections inside sewer pipes and other small spaces that present challenges for manual data collection due to accessibility issues.
Inuktun Versatrax 150
The Inuktun Versatrax 150 is another type of crawler inspection system. It is configurable, designed for long range use up to 500 feet, and commonly used to inspect tanks and pressure vessels as well as wastewater infrastructure.
Measuring devices are a type of inspection tool that helps inspectors collect measurement data, such as how long, deep, or wide something is.
Although there are some sophisticated digital measuring devices, many of the most common measuring devices are hand-held tools that don’t require any electricity at all, like calipers (shown below).
Here are some of the most common measuring devices out there:
- Engineering Square. Engineering squares help determine whether two surfaces are exactly perpendicular. They can also help draw straight lines.
- Protractors. Protractors are used to measure the angle between two surfaces (angle gages also do this).
- Levels. Levels measure the inclination of a surface relative to the earth’s surface. They range in complexity from fairly simple mechanical tools to sophisticated electronic sensors that can provide digital angular level values.
- Calipers. Calipers typically rely on a precise slide movement for measurements. There are several different kinds, and they can be used to measure a variety of things, such as depth and length or external and internal dimensions. Calipers can also be used to compare or transfer dimensions from one object to another.
- Gages. Gages are used to compare an object to a standard size. They can measure things like radius, thickness, angle, or bore size. A length gage is used to measure the length of an object, and a depth gage is used to measure the depth of holes.
- Micrometer. A micrometer uses a gage to measure very small distances. It does this by placing a surface or object between its two faces and moving one of those faces closer or farther away by turning a screw with a fine thread.