Claims
- 1. An apparatus for measuring variations in pressure, said apparatus comprising:
- means for containing a volume of liquid;
- an indicator float to be placed within said containing means and supported by said liquid contained therein, said float having upper and lower portions and a hollow interior portion for maintaining a compressible fluid therewithin, and being vertically movable within said containing means;
- means connected to said float for automatically providing a variable buoyancy equilibrium force to said float to offset buoyant forces created by said compressible fluid, whereby said equilibrium force is automatically varied in response to varying buoyancy of said float resulting from the changing volume of said compressible fluid in response to changing ambient pressures, said variable buoyancy means comprising a flexible ballast structure having top and bottom ends and supported adjacent its top end above the upper portion of said float such that said bottom end depends downwardly to said float; and
- means connected to the upper portion of said float for receiving a length of the bottom end of said ballast structure.
- 2. The apparatus of claim 1, further comprising means for adjusting the support of said flexible ballast structure above said float, said adjusting means comprising means for varying the length of said flexible ballast structure received in said ballast receiving means.
- 3. The apparatus of claim 2, wherein said adjusting means comprises a rotatable device about which said flexible ballast structure may be wound, whereby rotation of said adjusting means varies the length of said flexible ballast structure received in said receiving means.
- 4. The apparatus of claim 2, wherein said adjusting means comprises a winch-like assembly located above said indicator float.
- 5. The apparatus of claim 2, wherein said adjusting means comprises a winch-like assembly which can be operated to calibrate the apparatus to accurately reflect ambient barometric pressure by varying the length of the ballast structure received in said receiving means.
- 6. The apparatus of claim 5, wherein said winch-like assembly is journaled for rotation relative to said apparatus, whereby rotation of the winch-like assembly varies the length of the ballast structure depending toward said float.
- 7. The apparatus of claim 6, wherein said winch-like assembly further comprises a support rod journaled for rotation by application of rotation force to a crank, and wherein said flexible ballast is at least partially wound around said rod such that rotation of said rod adjusts the downwardly depending length of the flexible ballast as desired.
- 8. The apparatus of claim 1, wherein said ballast receiving means comprises a cup-like structure attached to the upper portion of said float.
- 9. The apparatus of claim 1, wherein said flexible ballast structure provides a predetermined buoyancy force per unit length which varies along the length of said flexible structure.
- 10. The apparatus of claim 1, wherein said flexible ballast comprises a chain.
- 11. The apparatus of claim 10, wherein said chain further comprises individual links of predetermined weight per unit length.
REFERENCE TO RELATED APPLICATION
This is a continuation-in-part of application Ser. No. 07/631,634, filed Dec. 21, 1990 in the name of the present inventor, now abandoned.
US Referenced Citations (8)
Non-Patent Literature Citations (1)
Entry |
Book 700 Science Experiments for Everyone Complied by Unesco. |
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
631634 |
Dec 1990 |
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