Pressure Transducer Operation and Data AnalysisAlena Voigt, Brian McLeod, Susan Konkol, Andrew Evans
What is a Pressure Transducer?
Our pressure transducer is much more precise so we can see very small changes in atmospheric pressure, our readings were every 5 seconds. The slightest change in pressure will result in not only a change in the graph but also a change in the frequency.
AmpCapacitorCalibrationOur pressure transducer.
How does a Pitot tube work? N1639DA 1952 Cessna 170B pitot tube, yes she still works great! Our pressure transducer can compare to a pitot tube in an aircraft.
They are used to tell pilots aircraft speed and some are even used to tell altitude (those are the more fancy ones).N1639DA more aerodynamic pitot tube.Random plane at PAQ
The Tunnel, 232 feet!!!
The set up.
DRI 4/19/10 Pressure Data & Wind Speed, 4-6 pm April 19th 2010, DRI
Pressure vs. time (In tunnel)
Pressure Relationship between the Tunnel ReadingsLow Frequency
Pressure and Frequency vs. Time
Pressure and Frequency vs. Time
Wind Speed for Multiple Days
Wind speed for April 11,12,13
Ten Day Pressure Trend, DRI vs. Ours Data From our Pressure Transducer
Different heights, two transducers instead on one.Air Base, blow stuff up, find pressure when explosions go off. - what a explosion would do to our pressure readings, and what frequencies exert the highest energies. Longer periods of time, to collect data, and analysis. Apply this method of collecting data over a multi-year period in order to forecast weather trends that may be expected in the future.
Our lovely title page and the peoples name that were in this group.*This slide was produced for the explanations of what a pressure transducer does. Our pressure inductor was made by us. Our professor made us a schismatic of what the transducer was suppose to look like and we went to work. It took a while because we had to solder maybe parts together. One of the pictures is our actual transducer that we made. The other is of a altimeter schismatic in a plane. More on how the altimeter plays in on the next slide. *This page was to inform people of what a pitot tube is. A pitot tube is a device used in aircrafts to measure pressure and some produce airspeed readings, these tend to be the more advanced pitot tubes though. In our experiment, I could relate the pitot tube to our pressure transducer the easiest. They seemed to go hand in hand with each other. *Here we see pressure shown as f(x) of time on a given 30 minute interval. Since pressure is a force and air molecules have weight, this force (measured in pascals) increase with decreasing altitude. When referring to the atmosphere, this weight is expressed in millibars (mb). In Reno, the average is around 850 (mb).This graph shows a total fluctuation of about .4 (mb) with decreasing pressure which might indicate some kind of weather coming in.*This is another pressure vs. time graph but outside the tunnel instead of inside on the same 30 minute interval.This graph shows a much larger fluctuation of 1.2 (mb) -However, shows a large dip in pressure, maybe due to sudden wind increase since the transducer was no longer protected in the tunnel.This trend doesnt follow that of the DRI data on the next slide. This might mean that pressure fluctuations are localized and vary widely over a specific area.*This DRI pressure data shows an increase in pressure over several hours rather than a constant decrease (which we saw on our transducer). Although the wind decreasing as the pressure increases does make sense. *This is a relation of pressure with time, including associated frequency components. This relation shows that different frequency sets are allowed to resonate on different scales as sinusoidal waves. -The lowest frequency set is showing much more spectral energy -We believe this is due to the fact that a lower frequency has a lower modal density allowing for more room for resonation. -The higher frequencies become more crowded and less able to resonate properly without interfering with itself.Average Frequency Resonation (Hz)(.2- 1.8) =4.5(2- 3.8) =2.14- 5.8) = 2.36- 7.8) = 2.518- 9.8) = 2.55
*This graph from outside the tunnel follows the same trend of the lowest frequency having much greater spectral energy. The mysterious dramatic drop in pressure demonstrates that pressure and frequency are inversely related in a sense.Average Frequency Resonation (Hz)(.2- 1.8) = 5.3(2- 3.8) = 2.4(4- 5.8) = 2.8(6- 7.8) = 2.9(8- 9.8) = 3The tunnel data also proved to us that on average the frequency components tended to resonate at a higher level outside the tunnel than within the tunnel; which was opposite of what we expected.*This comparison graph of pressure relationships at really low frequencies is a good example of how the lower frequencies respond more dramatically with higher pressure. - Obviously not the total millibars but rather taken from a fixed reference point.*These are the average pressure/frequencies for April 8-11, 16. The first and last days that data are graphed, April 6 and 16 are not 24 hr time periods so their graphs appear different. The frequency with the most energy on all of the graphs is the 0.2-1.8 Hz which is the lowest frequency. It tends to rise when the pressure is at a low or moving toward a low.
*On April 12, 2010 there was a high pressure system behind a low pressure system. We can see this from the pressure graph on April 12. Most of the graphs have a low pressure that starts about 8:00 A.M. and bottoms out around 4PM. April 12 has a little low at 4:00 P.M. but overall is moving toward a high pressure from about 8:30 A.M. to midnight.*The average wind speed for April 12 is higher than for the other days when data were taken.*The wind speed on April 11 is a little slower than on April 12. Then it increases on April 12 . It slows down again on April 13. This shows a pressure change on April 12.*Constant light blue = DRI This shows a pressure change near April 12.Multi color = Our data**