A device that can measure height

[chebyshevF]

A few shopping centres in my area have these devices that can measure your weight and height.

I figured I'd try it out, all you had to do was insert a $1 coin. Thing is, it has this type of tube on the top of it (the actual device was in an elongated C shape with a small platform to stand on), which is where I imagined it would emit some sort of radio wave(?) and pick up a deflection. So when I stood there, it felt as if my head had this sudden straining feeling, and it felt like for a bit after it was done.

I'm wondering whether anyone knows what I'm talking about and whether I have anything to worry about? The device had some sign on it that said "Health Warning" and a phone number, that was it.

 

[tiny-tim]

hi chebyshevF!

probably ultrasonic …

was it like this … http://www.goldshinechina.com/height-scale-and-weight-scale-JXHW-I.htm" ?

 

[chebyshevF]

Hey, thanks for the response tiny-tim!

Whilst it didn't look like that, it was in a very similar shape. The "spine" of it was curved and there was some sort of tube on the top, but I think it may have been put there for appeal.

So I'm guessing it must have been using ultrasonic waves, in which case I have nothing to worry about :) Probably just me being paranoid.