Cheap (ish) way to get PAR readings

[Spaced Cowboy]

[Note: This isn't *really* DIY, although you need a multimeter. Still, I didn't know it, and I thought it might be of interest to folks. You can see the results in the currently-last-post-but-2 in my build-thread]

An Apogee PAR meter currently runs to ~$370 if you figure in P&P and Tax. I didn't want to pay that much to measure the PAR from my lights, but I came across this little note in their FAQ:

The SQ-100 and 300 series are considered to be self-powered and have been calibrated to 5.0 µmol m-2 s-1 per mV. Use a voltmeter with a mV setting to attain better resolution. Connect the positive lead of the voltmeter to the red wire of the SQ and the negative lead of the voltmeter to the black wire of the SQ. Once you are reading the mV output from the sensor, simply multiply this reading by 5.0. This will give you the µmol m-2 s-1 output from the sensor, otherwise known as Photosynthetic Photon Flux (PPF) or Photosynthetically Active Radiation (PAR).

... the SQ-110 is "only" $139 (significantly cheaper than $329 for the meter) and if you can multiply by 5 and own a multimeter that's reasonably accurate at the 10mV to 250mV range (mine is, and it's an el-cheapo one off Amazon), this is a relatively easy and cheap way to get your readings.

Hope this was helpful to someone

Simon

 

[rps3]

Thanks, I've been looking for info like this for a while now... or rather have been interested in it but never looked deep into it. lol