Calibration of SF110

[bwoltz]

I've gone through most of the posts here and there is a lot of good information..

A question that has come up is about calibration using the calibration plate on a SF110

According to here, the 1.874 / 0.3125 plate flows 153.2 CFM at 10 inches.. In the Superflow manual published in 2005, the manual states that the % manometer should read 78% at 10 inches on the 185 scale and that all calibration should be based on this..

Lets assume that my plate reads 78% at 25 degree delta (it don't but I want to assume that it's perfect).. OK, 78% of 185 is 144.3 and I need to correct for the 25 deg delta. (x0.981) so the calculated flow of the bench is 141.6

This means that my bench is reading 0.924 (141.6/153.2) of what is should be reading.

If I up my calibration factor from 78% to 84.4% (78/0.924) then when I have a perfect bench I should get 84.4%

185 x 0.844 x 0.981 = 153.2


Now I'm right on...


Seem like the manual is messed up.. I shoud be calibrating off 84.4 not 78..

Any clue?

TIA Bruce

[49-1183904562]

Bruce;

Not sure but has the Inclined fluid been changed to a different SG.

This is what my older manual say's.

Rick



Edited By 1960FL on 1239312441

[bwoltz]

Rick, thanks for the older sheet.. I suspect now that in the conversion process they messed up.. The original process says take reading and multply x full scale to correct to 153.2.
153.3
CF = -------------------
Reading * 185

What they were trying to do was keep from having to multiply times 185.. If I take top and bottom and divide both by 185 I get..
0.83 or 83%
CF = ---------------
Reading

The manual I have says basically the same as your except it says

78%
CF = ---------------
Reading

So I suspect that the 78% is in error.


As far as SG goes, I'd thing that the readings could still be the same only the real pressure that you are testing at would be different since everything is based on the calibration plate.

This is a pretemp compensation for the plate so those with other systems that don't need temp comp should read

153.2 x 0.981 or 150.2 ..

Get that Dwight?

Thanks again..


Bruce

[bwoltz]

I scanned the document section that is the same.. Like I said, it seems like the were trying to make the calcs easier and messed up..

For anyone interested, I've done a excel spread sheet that all you have to do is setup the cal plate number, enter the max flow ranges for each lift measurement, flow % and temps.. It will calculate flow corrected to 10 and flow corrected to 28, plus port, valve throat, and curtain average velocities at 28..and plot the lift/flow curves.

It also corrects to 10 inches higher lifts that you SF110 may no be able to handle.. It's set up for pairs of heads like on an HD

Bruce