volume change sensors
volume change sensors
(OP)
i'm looking for sensors that can measure volumetric change to within 1 cc accuracy. if anyone knows of websites or companies from which i can get information about this that would be great.
thanks!
thanks!





RE: volume change sensors
RE: volume change sensors
RE: volume change sensors
What else to measure depends on the application.
RE: volume change sensors
RE: volume change sensors
RE: volume change sensors
You could also weigh it to the nearest gram (+/- density).
You could toss a pressure sensor into the depths (tall container better).
You could let it swing and measure the period.
Acoustic resonance in a partially submerged tube where the note is set by the fluid level at the bottom. That one might actually work pretty good...
This reminds me of the old joke about using a barometer to determine the height of a building. You offer the lovely and expensive barometer to the building's caretaker if he will just tell you how tall the building is.
RE: volume change sensors
RE: volume change sensors
RE: volume change sensors
Ultrasonic to the surface.
There are resistive ones.
Tuning fork may work in your app
RF Capacitive sensors.
But WOW! 1 cc out of a gallon is not going to be easy! You are talking about 2 hundredths of a percent!!
Say you poured your gallon into a tube to magnify the level change as VE1BLL suggests. Say the tube is 1 inch in diameter. Your column would be 294.267 inches tall(24.5 feet!) Now a one cc increase of this liquid would represent a column height change of 0.078 inches.
This is why no one does this.
How would you even know if you have an *exact* gallon to begin with?
Your only hope is to find something that does indeed measure the density of the water. Say a vibrating structure whose frequency changes with water density. Or an optical effect. Or measure a bulk capacitance change in the water.
The pressure sensor method may not actually work since the water column would get deeper but the water would be lighter. EEEEW!
RE: volume change sensors
You could quite easily conceive of a 1 gallon-20cc container with a 40cc syringe tube at the top and you'd be able to measure 1 gallon to better than 0.25cc.
TTFN
RE: volume change sensors
RE: volume change sensors
xnuke
"Do you think you used enough dynamite there, Butch?"
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: volume change sensors
I would try and isolate you level detector from the main tank. Can you add a calibrated cylinder to the side of the main tank, and have your sensor measure this alone. You could install a pressure sensor on this cylinder with very fine divisions; you should always have the same starting pressure assuming you put in the same amount of water.
Tofflemire
RE: volume change sensors
RE: volume change sensors
[A gallon jug with a stopper and a straw]
And a human.
RE: volume change sensors
RE: volume change sensors
"oscillating U-tube principle" Most interesting.
I would go with a density-meter method before trying to monitor the exact physical volume because the measured volume would no longer matter.
Thanks.