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The Four Cornerstones of Rugged Monitors for Harsh Environments

Industrial-grade, or more informally, “rugged” products are products that can withstand the rigors of harsh operational conditions. To achieve this goal, design engineers must concentrate on the following four cornerstones of the product’s design and verification process: mechanical design, environmental testing, choice of components and material, and electromagnetic protection.

Mechanical Design

Industrial monitors must be designed to handle random vibrations caused by machinery or vehicles passing nearby and shock resulting from unexpected, sudden changes in motion. In fact, the constant vibrations experienced by industrial products can be a major cause of failure. Since industrial monitors could be used in any number of scenarios, including offshore oil drilling, on ocean-going vessels, and other marine applications; railways, automobiles, and other rolling stock applications; as well as in manufacturing plants and power stations, you need to make sure that your industrial monitor manufacturer has designed for—and just as importantly, tested for—both vibration and shock.

Rugged, industrial monitors are typically designed with an aluminum die cast housing, since this choice comes with a long list of plusses, not least of which is aluminum’s ability to retain its strength at the high operating temperatures that industrial monitors must contend with. In addition, aluminum is lightweight, is resistive to corrosion, and has excellent electrical and thermal conductance properties.

Another important requirement for industrial monitors be to be fanless The problem with fans is that regardless of how big or small they are, they’re always in motion, and consequently, are subject to the wear and tear that comes from motion. If a fan fails, you could experience operational delays, or at worst, the your device’s circuitry could be destroyed by the heat.

One requirement for industrial monitors that you should not overlook is how the monitors will be mounted. The fact that you are limiting your selection to fanless monitors provides a certain amount of flexibility in this regard, since you won’t need to worry about airflow, changing fan filters, and related maintenance tasks. However, before deciding on a particular monitor, make sure it supports a mounting option that is safe and convenient for your application.

Environmental Testing

Being industrial often means being dusty, humid, and outright wet, and consequently industrial products must be designed to work reliably even when frequently exposed to such conditions.

Since water and dust protection are critical features for so many applications, the industry recognizes a standardized rating system for the level of protection offered by a device. The Ingress Protection (IP) rating uses a two digit code to indicate how well a device is protected from solid objects and water. Ingress protection is represented by IPxx, where the first x indicates the protection level against solid objects, and the second x refers to the protection level against liquids. For standard industrial-grade devices, the minimum recommended rating is IP30, which would mean protection against items over 2.5 mm in diameter. For the most demanding industrial applications, an IP68 rating would provide the best protection against dust and water. A good middle of the road value is IP54, which is often used to define what it means for a product to be "fully rugged".

Designing industrial monitors that can tolerate a wide temperature range presents an even greater challenge for manufacturers, since freezing cold temperature can cause white spots and LCD motion blur, and corrupt the output of onboard components in unpredictable ways. On the other side of the cold/hot spectrum, high temperatures can cause an LCD to turn dark because of the nature of the liquid crystal display. In fact, for most monitors, display stability cannot be guaranteed unless the average temperature stays between 0°C and 50°C. Consequently, monitors guaranteed to operate normally at an expanded temperature range, for example, between -15°C and 55°C, give industrial operators a safer solution for many industrial environments.

For industrial monitors, another (and perhaps more critical) issue is that the user must be able to see clearly what’s displayed on the monitor, even when viewing it in direct sunlight or under the glare of intense industrial lighting. In fact, some industrial applications, particularly those that must operate without a hitch on bright, sunshiny days, could require a monitor that can produce between 1000 and 1300 nits.

Choice of Components and Material

Touchscreens that use PCAP (projective capacitive) sensors are suitable for industrial applications, in part because the exterior surface of the screens can be covered with a thick glass plate or similar material, making the screens more resilient and better able to cope with the harshness of industrial environments. One of the major advantages of PCAP technology is that the sensitivity of the touchscreen can be improved to a high enough level, and the amount of noise minimized sufficiently, to provide users with a “glove-friendly touchscreen” that can be operated with rubber gloves.

Electromagnetic Protection

As you might recall from basic physics, electric currents give rise to electromagnetic waves that radiate outwards from the conductor. For most electrical devices, this type of radiated electrical energy is unintended, and could turn into EMI (electromagnetic interference) for nearby devices. This is particularly crucial for newer electronic devices, which require much less power to operate and hence are more susceptible to low EMI levels. Industrial monitors will more than likely be used in EMI-rich environments, and consequently should be designed to operate reliably under such conditions.

For an industrial monitor, EMI is a two-way street. That is, the monitor must not be susceptible to EMI produced by nearby equipment, and the monitor itself must not produce EMI that influences nearby devices. Industrial monitors use special shielding and implement clever techniques of isolating the internal electronics of the monitor to achieve the required level of isolation.

Moxa’s Rugged Monitor Solutions

Moxa’s rugged monitors combine the critical features needed to ensure the durability and reliability of the monitors when they are used for industrial applications. “Critical features” in this case refers to every part of the monitor, including the exterior housing, all of the internal components, and of course the focal point of the monitor, the screen. As a result, Moxa’s rugged monitors have a full range of features needed for successful, long-term use in industrial environments:

  • Flat panel mounting with IP54 ingress protection rating
  • Rugged aluminum housing
  • Projected capacitive multi-touchscreen technology
  • Wide operating temperature range
  • Brightness that exceeds 1000 nits
  • High resolution
  • Easily readable outdoors in direct sunlight

The bottom line is that Moxa’s rugged monitors are designed to operate reliably in a wide range of harsh environmental conditions, including environments that are subject to strong vibrations, extreme temperatures, and wet or dusty conditions.

For more information about this topic, download Moxa's white paper on rugged monitors here.

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