Mathematical integration without calculus

I show how to convert an area measurement problem into a mass measurement problem that is easier to solve.  In general, this idea of converting measurement problems into different spaces is very powerful, and may prove useful in the future.

Measure the mass of an eyelash with a DIY microbalance

I built a microbalance based on a design by Paul Grohe: http://www.youtube.com/watch?v=n90whRO-ypE

It is has a precision of about 5 micrograms, and I measured a single eyelash at about 35 micrograms.  The balance is built from an analog panel meter that is controlled by a servo loop which optically monitors the meter's position. Adding mass to the meter's needle requires that the servo loop add more current to maintain the needle's position.  This additional current is read, and converted to a mass value.

Use an oscilloscope to collect optical spectral data

I'm using my new Tek oscilloscope to collect data from a DIY spectrometer.  The scope is in X-Y mode with infinite persistence.  The X axis is controlled by the rotational position of the diffraction grating in the spectrometer, and the Y axis is controlled by the photomultiplier tube, which is detecting the spectra.  In this video, I discuss the scope setup, and in future videos, I will talk more about the spectrometer, and how to use it.