I need to accurately measure distances of up to one. maybe1.5 meters in an outdoor environment. Accuracy to 1/2" at the outside of the detection envelope is required.
I've looked at the Sharp IR distance sensors and they're usable - but I'm worried about condensation building up in humid environments. I've found a number of ultrasonic sensors that are accurate, versatile and weatherproof - but they cost a bleedin' fortune (usually > $250US) and I need two of them for each project.
So - two questions ...
First, does anyone know what that plastic is that they make those condensation-resistant bathroom mirrors out of ? If I put the Sharp sensors behind a thin sheet of that ... no more condensation problems. (power-consumption IS an issue here so heated optical windows are out of the question)
Second, has anyone come across an AFFORDABLE ultrasonic distance sensor roughly fitting my accuracy needs ? 1/2" at 1 meter is adequate but the thing MUST be capable of withstanding 100% humidity pretty much forever.
Any help appreciated. Reply to group.