Is anyone aware of an inexpensive tool or device that will allow me to measure the volume of an irregular shaped space (i.e. glove box)? The tried and true method of ping-pong balls is not very accurate and is difficult to perform on vehicle cabinets that are open in the vertical position.
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Volumetric Measuring Tool
- Thread starter mcpdx
- Start date
similar idea, use 1/4" or 1/2" styrafoam balls. If the volume can hold some weight, place a plastic bag in the volume and then fill with water, measureing how much water it will hold.
Or put a plastic bag in the volume and spray in foam. Remove bag and measure foam by water displacement or by weight (1 cubic ft foam weight .76 pounds, the foam block weights 1.52 pounds, the volume is 2 ft^3).
If one dimension is linear, then measure the area of the irregular by graph paper or weight and multiply the area by the linear dimension.
Or put a plastic bag in the volume and spray in foam. Remove bag and measure foam by water displacement or by weight (1 cubic ft foam weight .76 pounds, the foam block weights 1.52 pounds, the volume is 2 ft^3).
If one dimension is linear, then measure the area of the irregular by graph paper or weight and multiply the area by the linear dimension.
I am assuming you don't have a 3D model of the part you need to measure volume of. Most modeling programs have a volume calculation.
Do you have the part by itself? If it is a glovebox, I would seal it and submerse it in water. Just measure the volume of water displaced.
I don't know how accurate of a measurement you need, but keep in mind that the above method will include be the exterior volume, not the interior volume of the glove box.
-Reidh
Do you have the part by itself? If it is a glovebox, I would seal it and submerse it in water. Just measure the volume of water displaced.
I don't know how accurate of a measurement you need, but keep in mind that the above method will include be the exterior volume, not the interior volume of the glove box.
-Reidh
- Thread starter
- #4
Unfortunatly, we are measuring competitive vehicles and don't have the CAD drawings. Also, because these storage bins and cabinets are installed in the vehicles we can not remove them to perform water volume tests.
If only the volume of air could be measured like water we could place a baloon type device in the empty compartment and inflate it to fill all the voids. Any thought along these lines?
If only the volume of air could be measured like water we could place a baloon type device in the empty compartment and inflate it to fill all the voids. Any thought along these lines?
MacGyverS2000
Electrical
Take a long bag, similar to a dry cleaners cover, and invert it. Close the bottom portion inside the glove box and begin filling with water. Water will slip between the door crack and fill the bag, albeit slowly. 5-10 minutes later when the water no longer enters the box you'll have what you need.
Where's the complication in this method? How accurate would you need?
Dan - Owner
Where's the complication in this method? How accurate would you need?
Dan - Owner
Get a 'Balloon', it will need to be a fairly tough one which when fully inflated is quite a bit bigger than the space you are measuring.
Place in glove box (or whatever).
Almost close glove box, leave open just enough to either pull the 'valve' of the balloon out or maybe put some small dia tubing to the balloon.
Inflate the balloon to just over atmosphere. You want it to take up all the room but not build up much excess pressure. It may be better to evacuate the air from between the outside of the balloon and the walls of the glovebox but making a seal like this may be difficult.
Seal balloon.
Pull out the 'inflated balloon'.
Imerse in water, the water needs to be up to the top of the pan or spigot. You need to make sure and not immerse it too far or the water pressure will compress the air. I'm thinking a large but shallow pan. Maybe push the balloon down with a large board or something so it can spread out but not be submerged too far.
Measure the displaced water.
I'm pretty sure I missed something.
If the water insists on compressing the ballon you could put a pressure gauge on the balloon to see how much and compensate to adjust the volume.
The balloon wont actually be a ballon, I'm thinking something like the heavy duty bags they use in shipping or something.
Sounds mighty complex, someone must have a better idea.
KENAT, probably the least qualified checker you'll ever meet...
Reminds me of Archimedes and the king's crown. ;]
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Well ideally it would be inflate to atmosphere but this wouldn't push out the air between balloon skin and compartment.
I propose measuring the volume by displacing water.
If you don't use the pressure gauge then as air is compressible the water pressure would compress it as the balloon is submerged this would effect your volume measurement.
If you compensate for pressure difference with a gage reading both in the glove box and submerged in water then you're home free and can inflate to well over atmosphere to fill the gaps.
I'm thinking filling macgyvers2000 bag with dcastos balls (only maybe the really small ones like in bean bags) may be a better idea.
(macgyvers2000 & dcasto, that wasn't a joke at your expense)
KENAT, probably the least qualified checker you'll ever meet...
I propose measuring the volume by displacing water.
If you don't use the pressure gauge then as air is compressible the water pressure would compress it as the balloon is submerged this would effect your volume measurement.
If you compensate for pressure difference with a gage reading both in the glove box and submerged in water then you're home free and can inflate to well over atmosphere to fill the gaps.
I'm thinking filling macgyvers2000 bag with dcastos balls (only maybe the really small ones like in bean bags) may be a better idea.
(macgyvers2000 & dcasto, that wasn't a joke at your expense)
KENAT, probably the least qualified checker you'll ever meet...
MacGyverS2000
Electrical
Hey, I'm all for the bean bag beans idea... whatever gets the job done, and if you spill those a vacuum cleaner takes care of the mess.
Dan - Owner
Dan - Owner
Leaving the practical realm and heading into the theoretical world, you could seal the glove box so that it is airtight with the exception of an air-hose quick disconnect fitting. Using an air tank of a known pressure and mass, hook it up to the glove box until the tank and glove box are in equilibrium. You would know the air pressure in the glove box (same as air tank), and the mass delta of the air tank by weighing it after it has reached equilibrium with the glovebox.
From this, you could calculate the mass of air in the glove box, the density of the air in the glove box, and thus the volume of the glove box.
This would be a huge pain to perform, and you would need fairly accurate measuring equipment. But if you have an excess of time and money, I would highly recommend this method.
-Reidh
From this, you could calculate the mass of air in the glove box, the density of the air in the glove box, and thus the volume of the glove box.
This would be a huge pain to perform, and you would need fairly accurate measuring equipment. But if you have an excess of time and money, I would highly recommend this method.
-Reidh
1. Place a plastic liner in the cavity.
2. Squirt expanding foam sealant into the cavity. I suppose that I would try to get the softest version of that stuff from the <Home> supply <Depot> store or equivalent.
3. Cut out the foam block without destroying too much of the volume.
4. Put foam pieces into a container of known volume.
5. Fill the container to the level mark with water.
6. Remove the foam blocks.
7. Do the math: Max- Remainder = Cavity Volume.
TygerDawg
Blue Technik LLC
Advanced Robotics & Automation Engineering
2. Squirt expanding foam sealant into the cavity. I suppose that I would try to get the softest version of that stuff from the <Home> supply <Depot> store or equivalent.
3. Cut out the foam block without destroying too much of the volume.
4. Put foam pieces into a container of known volume.
5. Fill the container to the level mark with water.
6. Remove the foam blocks.
7. Do the math: Max- Remainder = Cavity Volume.
TygerDawg
Blue Technik LLC
Advanced Robotics & Automation Engineering
What about sand? Fills just about everything, easy to pour, easy to measure, easy to vacuum out, and fairly easy to reclaim from a vacuum cleaner. Blowing it in to vertical areas might be a bit tricky, but getting it out is certainly easy enough. And it's cheap...which makes accountants happy.
Not the most accurate of methods, but I figure it would get you close enough?
Not the most accurate of methods, but I figure it would get you close enough?
GregLocock
Automotive
I suspect the OP is measuring the luggage capacity of hire cars in order to benchmark them. Filling them up with sand is not going to make many friends!
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
Smaller spheres will be more accurate as the size of the sphere reduces, at some point this becomes trivial.
You can also estimate the packing efficiency of any size sphere.
This really isnt that complex, it all depends on the accuracy that you need from teh measurement, I'm sure that 1/4" beads would provide accuracy to <0.25ft^3.
I wouldnt use styrofoam, the static charges would just be annoying.
You can also estimate the packing efficiency of any size sphere.
This really isnt that complex, it all depends on the accuracy that you need from teh measurement, I'm sure that 1/4" beads would provide accuracy to <0.25ft^3.
I wouldnt use styrofoam, the static charges would just be annoying.
Small balls in big bag in glove box or other space (as I previously mentioned).
What I didn't make clear before:
Seal bag, 'burping' excess air.
Place bag in displacement tank, no need to measure packing efficiency.
Ta-da.
So what did I miss?
You maybe be able to do the same with sand but it will be heavy, and if the bag tears will be more difficult to clear up, probably.
KENAT, probably the least qualified checker you'll ever meet...
What I didn't make clear before:
Seal bag, 'burping' excess air.
Place bag in displacement tank, no need to measure packing efficiency.
Ta-da.
So what did I miss?
You maybe be able to do the same with sand but it will be heavy, and if the bag tears will be more difficult to clear up, probably.
KENAT, probably the least qualified checker you'll ever meet...
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