please check my numbers and thinking
if i get a *GO* ill find some tube and implement
im in a sweat to know what the pressures are in my air box .. before and after the filter
reference:
1]
U-Tube Manometer
2]
Sine - Wikipedia, the free encyclopedia
3]
Sine, Cosine, Tangent Chart & Calculator
with measurements expected on the order of 0ne inch of water a more sensitive device seems indicated than the vertical u-tube [see prior or ref 1]
for the vertical u-tube the formula pd = γ h = ρ g h applies using water as the working fluid and INAg as the measurement increment solving
pressure = Height
so one inch measure= one inch of water[ dynamic pressure measured]
for the inclined U Tube the formula pd = γ h sin(θ)
θ = angle of column relative the horizontal plane
with water working fluid
pressure = sine of the angle x height measured
examining ref 2 & ref 3 i find
angle 45 degrees = sine 0.70710678118654
angle 30 degrees = sine 0.5
angle 15 degrees = sine 0.2588
so does this mean that a U tube inclined at 30 degrees measuring 1 inch level difference is measuring 0ne half inch of water dynamic pressure at the test site?
and that a U tube inclined at 15 degrees measuring one inch level difference is showing 1/4 inch [+88 thousandths of an inch] inch water dynamic pressure at the test site ?
find a protractor . fabricate for a inclined u tube to measure 1.5 inches water
15 degree umm what about 6 inches
here is the one i really want .
Series 200 & 300 | Durablock® Solid Plastic Stationary Gage | Dwyer Instruments
would not that look spiffy on my panel
cost about $400 new, anyone happen to have one in a junk box they care to part with , i don't care if its in calibration or not