Public Lab Research note

Thermal Flashlight Calibration Nomogram

by mathew | July 13, 2012 20:22 13 Jul 20:22 | #2799 | #2799

In this Photo

In the photo above the temperature range is set to 0-30 degrees C, and the color divisions within the range are readable.

explaining the nomogram

The nomogram here is simple- the temperature scale is matched to the wedge-shaped rainbow of LED colors on the left side of the page, and the colors all converge to zero on the right. By moving the temperature scale across the chart so that the max and min boundaries of the rainbow touch the temperature scale at the same points as the max and min settings of the thermal flashlight, the range and sensitivity of the flashlight's colors will be visible in the width of the rainbow color bars on the scale.


Sara Wylie and I were just talking about adding external calibration to the Thermal Flashlight in the form of either switches (1, 2) or knobs (potentiometers).

Sara liked the flexibility of knobs, and the ability to set any range. The only issue was-- how do we display color division of the range without adding an expensive/complicated graphical display to the thermal flashlight. We both liked the idea of a paper chart, and I thought up this simple nomogram. (this page on making war game nomograms is a great expanation/tutorial for complex nomograms). More Nomogram design/math

Files Size Uploaded
thermal flashlight nomogram.pdf 117 KB 2012-07-13 20:12:37 +0000


Since many folks may be looking for narrower ranges, could we bias the chart towards that range? something like this:

Nomogram sketch

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totally. some sort of logarithmic curve makes a lot of sense-- the curve would reflect the inaccuracy of large ranges and give more accurate adjustment within the small ranges most used.

I'm going to try to mount the nomogram directly onto two slider pots and make it the adjustment interface too-- picked up a great joystick last night at dorkbot that I think I can hack quickly.

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