flow quik calibration with PTS plates

[Sir Yun]

I fiddled with my FQ based setup and I must say.. not all that bad.

As you can adjust the FQ with a pot meter at the back it tried centering aound each plate.

50-100-200 cfm.

I got the decent results using the 100 and 200 cfm plate and setting it slightly high for the 100 and slightly low for the 200 (which is only getting 16,5 ' depression and is then corrected).

When you start with the 50 CFM plate the numbers are very low. Using the 100 or 200 it is a lot better over a wide range just the low range (50CFM) flow reading are still too high (53.5 CFM) but I can live with that.

100 reads as 100.6 and 200 as 199.6.

The orifice in a pipe that comes with a FQ now reads 83,2 (it should read 80.9, but with the depression connected to the 2D takeoff in the pipe it reads 80.0).

I will ask Audie tech if they are willing to add a calibration section to the software/hardware, I think others have inquired as well.

So if you have a FQ setup I would suggest using the vacuum on the pipe-orifice-thing as it seems to be more in line what you get when using proper sharp edged orificia.

[Sir Yun]

I have since figured it out. I used the PTS plates to determine a trendline ( in excel using a scatter plot. its quite simple to do) so I can correct a large part of the deviation out. Audietech send me a update so that the CFM leakage actually works so you can simply use the fudge factor flow adjustment (in percentages) + leakage (a constant loss) on the bases of the trendline

It now repeats to +/- 0.5% ( different days and slightly different weather and temp) (on a head that flows about 121cfm) and has 'absolute' error ranging from about 1 % at lower cfm (50) to 0.5% at 100 cfm and )0.3 % at 200 cfm .

I'm well chuffed with that

all-regression-lines.gif

[ivanhoew]

nice job joost