IP65 Touch Screen Display

Photo courtesy of viagallery.com(CC Attribution)

It’s an easy mistake to make. You need an LCD touch screen monitor for use outdoors, so you find one that has an “IP65” rating. An IP65 rating theoretically means that the monitor is sealed from dust ingress, and waterproof enough to survive “jets from any direction”. So it must be weather proof and suitable for the job, right?

Well, the right answer here is “maybe”. There are more factors to check than just the IP rating, if you want the IP65 touch monitor to actually work well outdoors in all weather.
Electronic Weighbridge

Weighbridges can require outdoor IP65 touch monitors.. Photo courtesy of CDEGlobal(CC Attribution)

Ingress protection vs. Operability

The IP rating of any device is literally only an Ingress Protection rating against solids (eg. fingers, wires, dust) and liquids (eg. water). “Ingress” literally means “actually entering”, so the IP rating system is all about whether solids and liquids can actually enter inside a device (and hence cause harm). The first digit of the IP rating is the solid ingress rating, and the second digit is the liquid ingress rating. The meanings of all the numbers are listed in Wikipedia here, but for the purposes of our weather proof monitor, we’ll look at IP65. IP65 means “Dust tight, no ingress of dust” and “Protected against jets of water from any direction”. That sounds OK for outdoor use, as far as ingress protection is concerned. But for an LCD touch screen monitor to be usable outdoors, this is not the only concern. We must also make sure that the IP65 touch screen is operable in all weather conditions.

Touch Screen Operability

There are several types of touch screen on the market, including Resistive, Capacitive, Infrared, Surface Acoustic, and Projected Capacitive. Each kind has its own strengths and weaknesses, and hence they are suited to different scenarios. For more details check out this blog post on touch screen types. For all weather outdoor use, the best touch screen technology to use is a good quality Projected Capacitive touch panel. This is because of the following properties:
  • It is made from glass, and hence minimises “hazing” when viewed in direct sunlight (unlike resistive touch);
  • Being glass, it is tough and can be made with 3mm or 6mm thick glass, and it doesn’t deteriorate in the sun’s UV (unlike resistive touch);
  • It still works when the screen is wet, even with rain water pouring down the screen (unlike capacitive touch);
  • It still works in direct sunlight (unlike infra-red touch).
Hence, for outdoor use, not only should you pick an IP65 touch screen, but you should make sure it uses Projected Capacitive touch technology with a good quality touch panel.
Daylight readability is important

Photo courtesy of Wade Rockett(CC No Derivatives)

Daylight Readability

Another important thing is to consider how the images on screen will look when viewed in direct sunlight. Standard LCD monitors tend to only have brightnesses below 300 nits, which is too dim for outdoor use. You don’t want people to be straining and having to shade the screen in order to read what’s on it. So make sure your monitor is rated as “sunlight readable”, which typically means the brightness should be around 1000 nits or more.

Night Readability

If your IP65 touch screen needs to be used at night, you should also consider how it looks in pitch darkness. If the monitor is a high brightness unit, then at full brightness it will dazzle people’s eyes and make it hard to view at night. So the monitor also should have a wide dimming range, and preferably automatic dimming, so it detects the ambient light level and adjusts its own brightness to suit. These features are not so common on industrial LCD monitors.

Temperature Rating

Finally, consider how hot and cold the monitor could get throughout the year, in its installed location outdoors. If it’s in the full sunlight all day in a hot location in summer, could it reach 50 degrees C? If it’s in a cold location in winter at night, could it reach -20 degrees C? Many industrial LCD monitors are not rated for the temperature extremes of constant outdoor use. So you’ll need to find a model that has a wide enough temperature rating to suit your outdoor location.