Caibration Problems

[Brucepts]

Is your inclined manometer angle adjustable?

If it is, adjust it so one of your plates reads correctly and then test your other plates and see where you stand, keep adjusting the angle till you have a "best fit" for all your plates. This might take a few tries as your "0" mark will also change unless your incline pivot point is directly at the zero mark.

Hope this makes sense . . .

[Flathead]

Hi Bruce
Have tried adjusting inclined manometer to to get it right but manometer has to be almost vertical which seems way off?
Thanks

Grant

[1960FL]

Grant,

Can you please explain how your monometers are plumbed?

Also do you have any more pictures of the inside of the bench maybe somthing that shows the whole construction so we can see all the chambers and the air flow paths.

Rick

[Flathead]

Hi
Will do a sketch plan and post tomorrow.
Thanks
Grant

[Flash]

Grant,

Can you please explain how your monometers are plumbed?

Also do you have any more pictures of the inside of the bench maybe somthing that shows the whole construction so we can see all the chambers and the air flow paths.

Rick

Is your water gauge, that you read you 28" off of, a "U"-tube type or a single tube with a reservoir?

Grant, you said you had to tip the incline almost straight up!!!
Were are the two line from the incline attached to the bench?
One hose should be attached to the bottom or below the orifice plate in the bench and the other should be attached to the top or above the orifice plate.......this is also were your taking your reading, to set you 28" right?

The other end of you vac gauge(28" ) is open right?

If your 28" gauge us a U tube and you only counting the Numbers on one side.........This could account for having to raise you incline to almost vertical?
If its a U shape tube, and you are only counting the numbers on one side. and have it a 28" of vacuum, you are actually reading at 56" of vac not 28!

This is what i did when building my water gauges. About pull out what little hair i have left.
But these guys are GRATE!!!!! They help me threw all my pit falls, and they will you as well.

A drawing will help a lot.......a couple of picture would help some more.
Just keep answering and asking question, read up on what they suggest and you will get it all figured out

[Flathead]

Hi
After much messing round to get PDF downsized there should be attached a sketch of basic layout drawing doesn't comply to any drawing convention so hope it is clear enough. In regard to plumbing and manometer questions
The test pressure manometer is simple water filled U tube one end open to atmosphere and one end to under bench top plate calibrations at 1" vertical equals 2" of water. The inclined mano is plumbed each side of metering plate. Presure tap locations are indicated on drawing.
Thanks again for input.

Grant

[Brucepts]

First thing I would do is verify your incline manometer is working correctly. T one end into your static pickup one end open to atmosphere (this will depend on flow direction on your inclined manometer) and run the bench up to the same pressure your incline is raised to ie 6,8 10 12" etc. If you don't have a T fitting just swap out the lines and do not make any changes while doing this to your static settings on the bench.

Now hook the T connections to the top pickup above your plate and verify this readings is the same. Do the same thing with the bottom pickup. I have had one person who had a clogged pickup/line and it acted like what is happening to your readings.

[Flathead]

Hi
Tested inclined manometer seems to be pretty accurate 14" rise 14" on U tube at all points I tested this without any metering plate installed. The inclined manometer can break through pretty easily so I will extend the incline below the end of the aluminium angle my tube is glued to. I guess I'm wondering what will happen once I install a metering plate will do that in the weekend maybe the flow in the box is impacting somehow on one of the pressure taps is that possible or does anyone have any other thoughts. I was thinking of shrouding the taps somehow??
Anyway thanks again.
Grant

[Brucepts]

Yes, it is possible to get impact pressure on a pickup.

I use a .040" hole in my pickups.

[1960FL]

100/200 25% should be 50% on inclined manometer 100/150 64% should be 66% 150/200 65% should be 75%. So what have I done wrong?

Grant I am going to go out on a limb here but just where did you get your % scale from?

I think you should go throught the calibration using pure math in the spreadsheets posted. In this the incline reading needs to be converted to actual inches of rise (i/e 10" on a 45° incline is only 5" WC).

Then this data plugged into the flow through an orifice sheet.

Rick