Taking shop data cheaply

I don't consider this off topic, since it relates to measuring things with your PC; could be in the shop or elsewhere. This is just a report on a neat, cheap device that works for me.

I just bought the $199 HF solar collector outfit just to stick my toe in the water with photovoltaic solar (PV, they say).

Back in 2003, I saw an ad for a data acquisition unit that plugs into the back of the PC, into a serial port and using a com port for interface.

This company, Dataq

makes a lot of different DAUs (Data Acquistion Units), at a lot of different prices. The one I bought costs (still) $25 and includes the hardware to read in 4 analog channels and 2 digital channels and some Windows based software (on CD)that allows you to graph and record the signals. Even comes with a screwdriver to tighten the wires onto the terminals). It is the model DI-194RS.

I have it hooked up to my new solar collector where it is happily taking readings on the collector voltage and total current.

There are some limitations on voltage input +-10 volts max, and the software could do a lot more. But with a well chosen shunt for the current and a voltage divider for the collector ouput, the graphing system is perfectly usable. Beside, you can export the data to Excel anyway. The only other limitation of note is that the analog channels are not isolated from eachother, so it may take a little creativity in that area. Anyway, I am tickled with the device. It cost only $25! The next higher featured unit is about $300 and they go up from there, but so what?

Should be adaptable to lots of uses. A great way to get familiar with data acquisition.

Pete Stanaitis

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