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  • Author Author: dubbie
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TempMeter#2 : Improved Accuracy by Using a Laser Poiter

dubbie

Proving Science

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Although my original Tempmeter (TempMeter : Measuring Temperature with a Brass Rod  ) does successfully measure temperature it requires quite a large temperature change to create a visible alteration to the indicator. It was suggested that by Dave Ingles and John Wiltrout that a mirror could be used with a laser to increase  the sensitivity, so I thought I would try it out.

 

I 3D printed a small holder for some circular mirror pieces that I happened to have, putting two identical mirrors either side of the 1 mm rod used to make the pointer turn. See below. I used two mirrors to balance the unit and avoid any turning torgue problems.

 

 

It is essentially just a small washer shape with an indent each side to hold the mirrors and a 1 mm hole through the side.

 

I used a small laser pointer (it's a cat's toy!) Bluetac'ed onto the side of the piece of reconstituted marble stone and adjusted to shine onto the centre of the small mirrors. The complete working system is shown below in the video.

 

 

After trying the ceiling as the display I thought I would try using a wall instead to see if the movement was more visible and it was.

 

 

I also noticed that the laser dot seemed to be sensitive to vibration as well. It seemed to me that if I tapped the stone base that the laser dot did jiggle slightly. It might have just been my eyes but it would make sense that if you make the system sensitive enough then it will measure vibration. Maybe it could be a combined temperature and vibration measuring meter!

 

Dubbie

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  • Hi Dubbie,

     

    Very well done. It was fun to see the lazer dot run across the ceiling. Even the slant of the ceiling served to amplify the effect.

     

    John

  • in reply to jw0752

    John,

     

    I originally displayed on the ceiling with the hope of getting that increased sensitivity effect, but it was really hard to hold the camera in one hand, heat the brass rod and keep everything stable. It was much easier to see on the wall. I did think about extending the length of the brass rod by soldering two of them together, in order to increase the movement, but it does not seem necessary with this much longer pointer.

     

    Dubbie

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  • in reply to jw0752

    John,

     

    I originally displayed on the ceiling with the hope of getting that increased sensitivity effect, but it was really hard to hold the camera in one hand, heat the brass rod and keep everything stable. It was much easier to see on the wall. I did think about extending the length of the brass rod by soldering two of them together, in order to increase the movement, but it does not seem necessary with this much longer pointer.

     

    Dubbie

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