Solar-Powered Tape Measure/Calculator Requires Pencil Backup

Ian Benton sends in this submission of a solar-powered device with an interesting backup mechanism in the event of a power failure:


” Iwas once given a combined tape measure and solar powered calculator like this one. I thought it would be handy for working out the area of a room. I measured the length, and entered it into the calculator memory. I then measured the width of the room. In doing so, my hand covered up the solar panel that powered the calculator, which caused it to lose the number in its memory.

Now I know why it includes a notepad and pencil! I suppose I could use the calculator to convert inches to millimetres, but the tape is already marked in both imperial and metric.”



  1. I’m sure you’re right, Mark, that was the intention. You’ll just also need a tape measure to carry out the measuerments, so you have something to write down (when the power is lost)!

  2. Is it possible that the pencil & paper are to make a noite of your measurements or would that possibly be too obvious?
    As suggested this is more used by monkeys 😉

  3. Now if there was generator geared to the spool of the pul out tape measure the calculator would get a boost of power each time a measurement was made.

  4. I have one of these – and I agree that the calculator is almost a waste of space because its so easy to cover the solar panel and thus loose what you’ve entered. (Its not quite so bad if you take it out first.)
    To make matters worse, the calcular slides in and it relies on an interference fit to keep it in place. On my one I find that if I hold it at the wrong angle the calculator falls out. I often had to search for where it might have fallen out – although now I don’t use it except occasionally for the tape measure.

  5. FOllowing up on Yimmy’s post, perhaps this segment should be renamed as “Used by Monkeys”.

  6. The obvious reason for the pencil would be to mark what you’re measuring….

Leave a Reply

Your email address will not be published. Required fields are marked *


You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>