Ergonomically designed handheld thermal imaging devices

Tuesday, October 28, 2014: Thermal imaging devices are widely used in the electronics industry and have proved invaluable in both production and diagnostics. They are fantastic maintenance tools and are equipped to handle evolving industry requirements

By Richa Chakravarty

Thermal or infrared (IR) energy is light that is not visible to the human eye because its wavelength is too long to be detected. Thermal imaging involves the use of cameras constructed with speciality sensors that can see the thermal energy emitted by an object.

The ability of thermography to view small, irregular-shaped objects, and to remotely determine thermal characteristics and temperatures, has been a great asset to electrical engineers and technicians. Rather than measuring temperature in units alone, thermal imaging devices or cameras take a picture showing the temperature differences on a surface. Thermal imaging devices are widely used in the electronics industry and have proved to be invaluable in both production and diagnostics.

How they help

One of the strengths of the technology is that it requires no contact. Live systems of dangerously high temperatures, electrical currents or high speed moving parts can all be inspected. So, from a safety point of view, it has some real benefits. In high value processes, the cost of maintenance can be greatly reduced by predicting when repairs or routine maintenance are needed. This enables maintenance to be planned, which in turn can minimise costly downtime.

Since many design and manufacturing flaws manifest themselves thermally, product design teams find it beneficial to use thermal imaging devices that quickly identify electronic and electrical problems in their products before breakdowns actually occur. Whether it is designing circuit boards or satellites, thermal imaging devices can enable companies to maximise production efficiency, minimise time to market, and avoid costly recalls and warranty issues.

Thermal imaging devices in electronics are typically used to inspect electronic and electrical components and sub assemblies, circuit boards and assemblies. There can be several reasons for temperature hotspots or deviations including under-designed components, component failures, improper soldering, broken traces, reversed polarity, etc. Thermal imaging devices can rapidly scan a surface that is non-destructive and environment friendly, enabling quick detection of potential problems or defects. This reduces the time spent in troubleshooting.

The latest in the market

Thermal imaging cameras do not actually ‘see’ temperature. Instead, they capture the IR energy transferred from an object to its environment and produce a real time image in a colour palette, where hotter objects appear brighter and cooler objects appear darker (depending upon the palette chosen). Handheld thermal imaging devices are popular because they are portable and can be used at a safe distance from the process or equipment that needs to be monitored—they require no direct contact with dangerous surfaces. Here are some other advancements that these handheld thermal imaging devices now feature.

Multi spectral dynamic imaging (MSX): This is a real game changing technology that has been introduced in the market. A regular thermal image only displays heat signatures, so key details apparent to the eye can be lost in the haze if they are of similar temperatures. FLIR cameras with MSX use digital camera to enhance the thermal image. The high contrast, ‘skeletonised’ image allows for key aspects of the visible spectrum to be overlaid on top of the thermal output, while still keeping the important thermal information prominent.

FLIR’s handheld thermal products come with this new MSX feature. “The patent-pending technology is based on FLIR’s unique onboard processor that provides extraordinary thermal image details in real time. MSX incorporates real time thermal video enhanced with visible spectrum definition. It produces excellent thermal clarity to highlight exactly where the problem is. MSX ensures easier target identification without compromising radiometric data,” informs T P Singh, sales director, India, FLIR Systems India P Ltd.

Fine resolution capability: With the focus on predictive maintenance, thermal imaging devices provide clear and sharp images due to their unique, fine resolution capabilities. These models not only provide insulation resistance, but come with wireless testing and report-generating capabilities. The U5855A true IR thermal imager introduced by Keysight Technologies allows engineers to safely and efficiently identify potential faults without shutting down the systems or disrupting the productivity of an industrial plant. The fine resolution capability allows the U5855A to achieve an effective image resolution of 320×240 pixels from a 160×120 pixel detector. With this feature, the U5855A provides four times higher resolution than typical 160×120 thermal imagers. Together with a 4x digital zoom, the U5855A reveals finer details, especially when inspecting small cracks on industrial pipelines even from a distance.

“The U5855A’s light and ergonomic design allows engineers to comfortably use the thermal imager for longer periods of time, and operate it single-handedly in tight locations. Users can also easily change settings or access frequently used functions such as the torch light, laser pointer, auto scaling or trigger, with quick access buttons. With in-camera monitoring and analysis capabilities, the U5855A saves time by eliminating the need to connect to a PC,” shares Rajesh Sawant, business development manager, Keysight Technologies India Pvt Ltd.

Next generation auto focus: Every IR camera user knows that focus is the single most important thing when conducting an IR inspection. Without an in-focus image, temperature measurements may not be accurate, sometimes being off-mark by as much as 20 degrees, making it much easier to miss a problem. Fluke’s LaserSharp auto focus tells users exactly where they are focusing. The Fluke Ti400 infrared camera is equipped with laser sharp auto focus for perfectly focused images. “It uses a laser to calculate the distance from the target, before it focuses. It first places the red laser dot on the equipment that needs to be inspected, then pulls and releases the trigger for a perfect in-focus image. Along with this, it offers firmware updates to help find problems faster, which allows the user to capture up to five additional measurements by enabling the CNX wireless system on the thermal imager,” adds Rajesh Tawani, senior product manager, Fluke India. These additional measurements help diagnose problems faster and provide additional data to create more comprehensive reports.

High inspection capabilities: For demanding environments, especially in the research and development segment, manufacturers have recognised the need for specialised high performance thermal imaging systems. To support the wide and varied demands of this market, they are offering high-specification thermal imaging cameras that deliver top quality results for even the most challenging applications. FLIR’s Ex series of cameras are point-and-shoot thermal imaging devices that give users access to a new dimension in inspection capabilities. A FLIR Ex series camera is an affordable replacement for a spot pyrometer. It provides a thermal image with temperature information on every pixel. The combined image storage space of the new imagers with MSX, for both thermal and visual formats, makes the cameras very easy to use.

Making a purchase decision

There are lots of choices in handheld thermal imaging devices, ranging from extremely affordable point-and-shoot models to highly specialised models in the HD-level. But finding the right fit can be a daunting task. Thermal imaging cameras perform an essential control function in major manufacturing industries. By monitoring the temperature, users can control entire factory production processes as well as ensure the highest quality standards. Here are a few factors that users should keep in mind before buying a handheld thermal imaging device.

Resolution clarity: Most IR cameras have fewer pixels than visible light cameras, so one must pay close attention to detector resolution. It is better to buy an imaging device with the highest detector resolution or image quality that the budget allows. “Along with a good resolution, ruggedness and user friendly software, the user should also check the availability of lenses for different applications,” shares Rajesh Tawani.

Accuracy: The buyer should select an imaging device that delivers accurate and repeatable results. IR cameras do not just let the user see differences in heat—they measure those differences. This means the accuracy and consistency of the measurements is a very important factor when determining the value of a camera.

Ergonomic design: New test and measurement tools now allow certain thermal cameras to measure more than temperature to fully quantify the severity of moisture damage and electrical issues. These moisture and clamp meters wirelessly transmit vital diagnostic data such as humidity, amperage, voltage and resistance, directly to the camera. Users should make sure to get a camera that makes their jobs easy. They must choose a thermal imaging device with a wide temperature range so that they can measure ambient and high temperature spots in the same image. Also, a comprehensive, extended warranty programme protects users’ investments over the long haul.

“The main thing that users should keep in mind is the instantaneous field of view (IFOV), which is a calculation of the size of the smallest object that can be viewed or resolved at a specific distance from the camera. Then comes the temperature range, ease of use functions, picture quality, and Wi-Fi connectivity with the latest electronic gadgets. It is best to watch an actual demonstration of the product before taking a final decision,” advises T P Singh.