Method and apparatus for reducing error when measuring minute quantities of weight
View Patent ↗The invention relates to an instrument and method for measuring minute quantities of weight, including a pan for holding a sample to be weighed, a chamber for forming an enclosure about the pan, and a hang-down wire coupled to the pan for suspending the pan within the chamber. The pan has volume less than 0.020 cm 3 and the hang-down wire has a volume less than 0.01 cm 3 . The invention may also include a carrier gas, placed within the chamber, having a generally consistent density over changes in temperature.
1. An instrument for measuring weight, comprising:
a pan for holding a sample to be weighed;
a chamber for forming an enclosure about said pan;
a hang-down wire coupled to said pan for suspending said pan within said chamber and adapted to be coupled to a weight sensor;
said pan having a volume less than 0.020 cm 3 ; and
said hang-down wire having a volume less than 0.01 cm 3 .
2. The instrument according to claim 1 , said pan having a volume of less than 0.009 cm 3 .
3. The instrument according to claim 1 , said pan having a volume less than 0.005 cm 3 .
4. The instrument according to claim 1 , said hang-down wire having a volume less than 0.008 cm 3 .
5. The instrument according to claim 1 , said hang-down wire having a volume less than 0.006 cm 3 .
6. The instrument according to claim 1 , wherein said chamber further includes a carrier gas.
7. The instrument according to claim 6 , wherein said carrier gas is helium.
8. The instrument according to claim 6 , wherein said carrier gas is hydrogen.
9. An instrument for measuring weight, comprising:
a pan for holding a sample to be weighed;
a chamber for forming an enclosure about said pan; and,
a hang-down wire coupled to said pan for suspending said pan within said chamber and adapted to be coupled to a weight sensor;
where said chamber includes a carrier gas being hydrogen.
10. The instrument according to claim 9 , wherein said carrier gas has at least a second part being a reactant gas.
11. A method for measuring weight, comprising:
providing a pan having a volume of less than 0.020 cm 3 for holding a sample to be weighed;
forming an enclosure about the pan;
suspending the pan within the enclosure with a hang-down wire having a volume less than 0.01 cm 3 ; and
coupling the hang-down wire to a weight sensor.
12. The method according to claim 11 , further comprising reducing the volume of the pan to less than 0.009 cm 3 .
13. The method according to claim 11 , further comprising reducing the volume of the pan to less than 0.005 cm 3 .
14. The method according to claim 11 , further comprising reducing the volume of the hang-down wire to less than 0.008 cm 3 .
15. The method according to claim 11 , further comprising reducing the volume of the hang-down wire to less than 0.006 cm 3 .
16. The method according to claim 11 , further comprising placing a carrier gas within the enclosure having a density that is generally consistent over changes in temperature.
17. A method for measuring weight, comprising:
providing a pan for holding a sample to be weighed;
forming an enclosure about the pan;
suspending the pan within the enclosure with a hang-down wire;
adapting the hand-down wire to be coupled to a weight sensor; and
placing a carrier gas within the enclosure having a density that varies less than approximately 0.09 g/cm 3 over a temperature range from approximately 0-400° C.
18. The method according to claim 17 , further comprising reducing a volume of the pan to less than 0.009 cm 3 .
19. The method according to claim 17 , further comprising reducing the volume of the hang-down wire to less than 008 cm 3 .