Today I got this meter at the factory that I currently work, For further extreme testing.
In there, there are lots of big and tall buildings ,
so it was an large scale test area ..
Just one of the 8 major “ work shops “ in it .
Its 80 meters long , 25 meter wide , and 16,34 meter tall .. (crane bridges moving around in it)
Well I have mixed feelings , about my findings ,
As I discovered the true capabilities of those ultrasonic devices.
This technology are based on sound , the device its an sound source of 40KHz ,
The returning “ reflected “ sound , it’s the measured portion.
But the “ reflected “ sound , in order to be reflected , it must hit on something that reflects the sound back .
So I tested the meter on several type of surfaces .
And found the limits .
The good part about the meter , are that if it did not gets an specific amount of reflected sound , it does not give an reading at all .
So there is less chance to get an false measurement , at the worst scenario ,
You will get an “ error “ message from the device , and no numbers.
And now the data of my tests .1)
Perfect finished wall and painted = 19.90 meters Max detectable distance. 2)
Metal large doors - full metal surface = 11 meters Max detectable distance.3)
Wall covered with tiles = The most lovable surface for measurements by the. meter … my testing area was like 12 x 12 meters , and as I said the meter loved the tiles . 5)
Wall with common red bricks = 10 meters Max detectable distance.6)
Wall with covered with plaster , but with the technique of “ Sprayed plaster ,
By machine …. Its full of uneven spots , looks like an sponge , and it was the worst material for this meter , the detected distance dropped to just 7 meters . Extra remarks …
This meter are suggested to be used at fresh finished buildings,
That they are still totally empty ( no furniture ).
When the measured space has objects in it , you must do several testing measurements, so to find the most clear optical line , across the room.
The only fool proof measurement with it , are the distance between the floor and the ceiling .
But for my taste , it’s the most important than all , and the most hard to make with any other alternative way !!
So , now with all this new details in mind , I continue to give to it,
my thump up.
Because, at the end of the day , it will do what it promises .
One last thing that impressed me , was that if you step at the center of the measured area , you can measure on an average rate about 15 meters in front of you ,
And by turning your body 180 degrees another 15 meters at the back .
So you can do safe measurements with out the assist of an second person ( tape meter) , Up to 30 meters .
And with the same technique ( front + back) , even at the worst surface like the spayed plaster ( material cement ) , there is 14 meters of measured distance.
I had one conversation on the job, about alternative “distance measuring systems” with laser pointers.
Well, they do exist .
But , how they will measure anything .... at out-door ... with a bright sun light ?
The ultrasonic meter did not care about the sun light,
and it offered reliable hand held measurements , with out tripod on daylight . Conclusion
… If there is an silent battle, between ultrasonic VS laser,
Both contesters haves their weak points.