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Volumator
For measuring the volume of complex spaces. | |
The Volumator is a very simple device for measuring the volume inside sealed spaces. Instead of using fluid volume, the Volumator uses the change in pressure with compression. To do this a known volume of air is injected into the unknown volume from a cylinder of known dimensions then the change in pressure
is read directly from a gauge. This gauge would not only be calibrated to give accurate measures at 1 pump, it would also have parallel scales for multiple pumps to give accurate measures for larger volumes. The needle on the gauge locks at the peak pressure and must be manually relieved for each new test.
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Nice idea. What kind of tolerance / accuracy would we be talking about? |
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given quality tooling and calibration center scale values should be +-1% with linear falloff given multiple pumps. Due to the logarithmic nature of the data the user must be trained to use the tool accurately. An automated version could also be produced where the user pumped the handle and the chip gave a corrected average of peak samples and then interpolated a "flex factor" to additionally give the rigidity of the space. A protractor tool could be developed to do the same thing for the simple gauge tool. |
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V1, V2 might be good. V3 would be marginal and I haven't bothered to see V4 yet. |
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It's going to need temperature compensation too. |
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If the pipe between the cylinder and the measured volume is small, turbulent flow will cause Joule heating, thus affecting the accuracy of the device. |
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Using a microcontroller to sense Delta-T and apply the General Gas Law is simple enough. |
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Flows of gas will need to be slow and smooth. |
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How does the tool cope with non-sealable spaces? |
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