Mark

As I recall I recommended it with Linux for email :) Of course it is
now about 5 years old and you know how fast computers become obsolete :)
Tablets are taking over this segment of the market using a form of
Linux called Android. If it is any consolation full blown Linux does
not work on it worth a damn either. The original Asus Eeee OS, a sub
set of Linux, worked OK.

Good work. Your on your way. I am glad to see Bobby involved as we
should see data from both a 2 rotor supercharged (RV10) and a 3
rotor P-port.

Paul Lamar

Paul,

I thought we bought them to use in flight, above 10k, hence the SSD.

What voltage range should I be seeing from the pressure sensors.  The
iDAQTest&Log 3.1 shows 1.717v for atmospheric, and .0077v at 25" Hg.
   Does this sound about right?  How do I convert this to MAP?

Mark

Yes it is good for that.

What is the pressure sensor part number you have?

Here is a graph for a 4250.

Tracy is know using the 2 atmosphere 4250 above version I think.

Paul Lamar

Here is the graph in PSI as well.

Paul Lamar


Paul,

According to my understanding, I should be reading approx. 17" hg or 57
kpa at idle; which would be a voltage of approx. 1 volt. but I'm
actually only reading .597v.  As vacuum increases, the voltage readings
get smaller (.400v @ 20", .0077v @ 25").  Does this sound correct?

As an example, if I pump it down to 25" Hg, that's equivalent to -85 kpa and the Hytek shows .0077v.


Mark
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Yes that is correct. The gage on the pump is called "gage" pressure
of all things :) Sea level is zero. Vacuum is minus and up-and/over sea level is plus.

These are so-called absolute pressure sensors.
Think of a a vacuum as low pressure. Zero pressure is outer space.
One side of the tiny diaphragm is near zero pressure. The resolution is remarkabler and that is why Tracy can use the two atmosphere version for the normally aspirated engines as well as the turbo.

0.597 volts is about 7.250 psi which is surprisingly high to me. Not out
of the real of possibility however. What is the fuel flow at idle?

The real beauty of this HyTek data acq system is the stand alone 12 bit analog to digital converter. The resolution of this jewel is one part in 4000 so set your spread numbers to be at least 4 digits. There is a world of difference between .597 volts and .598 volts :)

BTW That is a very good hand vac pump that can get down to 2.xxx psi
absolute pressure.


Paul Lamar