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.
Ingress protection vs. OperabilityThe 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 OperabilityThere 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).