monday, june 17th

Georgette found 9 articles relating to CO2 and IAQ.
Sherin and I tried to measure the speed of a fan based on its voltage from 5 to 12 volts. The first method  we used was with a photo gate which should have measured the time for the fan to turn 40degrees. After about 50 measurements, I discovered a problem. I dont think the photogate was fast enough to measure the speed of the fan...UGH! I then hit upon the idea of using the pitch of the fan as a speed indicator. Using an online frequency generator and my techniques aquired in many years of band, I was able to match the generator to the pitch of the fan and get a measurement to +/- 1Hz.  I was also introduced to Dr. Garcia and he showed me some sound analyzing equipment. He was very kind, but I was almost already done.  Disappointment #2 of today was trying to measure the speed of the gas in the tube as the fan pulls it through.  I was going to measure the pressure drop in side the tube and use Bernoulli''s Law to find the speed. The pressure sensor, however, was not sensitive enough to measure the drop in pressure.  Based on the data sheet ( which is junk), the air should have been flowing at 17m/s. My guess would put it at under 2m/s. Sheesh!  Disappointment #3 was finding out that we may need to change from CO2 to VOC which would negate the work we have done looking in journals, experimental setup, etc......frustrated,
Dave