Balance with a heat removing device
View Patent ↗A balance ( 1 ) with a weighing pan ( 3 ) inside a weighing compartment ( 2 ) enclosed by a draft shield ( 4 ) has at least one thermoelectric module ( 16 ) that is arranged outside of the weighing compartment ( 2 ) and thermally connected to a stationary part of the balance ( 1 ). At least one vertical wall ( 8 ) of the draft shield ( 4 ) has a lower end portion in thermal connection with the thermoelectric module ( 16 ). The vertical wall ( 8 ) is configured in such a way that a temperature gradient develops in the vertical wall ( 8 ), wherein the temperature increases from the bottom to the top of the wall ( 8 ).
1. A balance ( 1 ), comprising a weighing pan ( 3 ), a weighing compartment ( 2 ) surrounding the weighing pan on all sides, a draft shield ( 4 ) enclosing the weighing compartment, and a stationary part, wherein the draft shield has at least one vertical wall ( 8 ) formed as a component of the stationary part, wherein at least one thermoelectric module ( 16 ) is arranged outside of the weighing compartment ( 2 ) near the stationary part in a lower portion of the balance and thermally connected to the stationary part, wherein the at least one vertical wall ( 8 ) has a lower end portion in thermal connection with the thermoelectric module ( 16 ), and wherein the at least one vertical wall ( 8 ) is configured in such a way that a temperature gradient with a bottom-to-top temperature increase develops in said at least one vertical wall ( 8 ).
2. The balance ( 1 ) according to claim 1 , wherein the stationary part of the balance has a floor plate ( 11 ) extending over the entire length of the balance ( 1 ) and consisting of a material with good thermal conductivity, said floor plate ( 11 ) being in thermal connection with the at least one thermoelectric module ( 16 ).
3. The balance ( 1 ) according to claim 1 , wherein the stationary part includes a measuring cell compartment ( 9 ) and a balance housing ( 10 ) surrounding the measuring cell compartment, and wherein the at least one vertical wall ( 8 ) is configured as a separating wall between the weighing compartment ( 2 ) and the measuring cell compartment ( 9 ).
4. The balance ( 1 ) according to claim 3 , wherein the measuring cell compartment ( 9 ) contains air with a vertical air temperature gradient with a bottom-to-top temperature increase.
5. The balance ( 1 ) according to claim 1 , wherein the weighing compartment ( 2 ) at least near the weighing pan ( 3 ) contains air with a vertical air temperature gradient with a bottom-to-top temperature increase.
6. The balance ( 1 ) according to claim 1 , wherein respective temperatures in an upper end and a lower end of at least one of the at least one vertical wall ( 9 ) and the weighing compartment ( 2 ) differ by substantially no more than 1° C.
7. The balance ( 1 ) according to claim 6 , wherein said respective temperatures differ by substantially no more than 0.5° C.
8. The balance ( 1 ) according to claim 3 , wherein respective temperatures in an upper end and a lower end of the measuring cell compartment ( 9 ) differ by substantially no more than 1° C.
9. The balance ( 1 ) according to claim 8 , wherein said respective temperatures differ by substantially no more than 0.5° C.
10. The balance ( 1 ) according to claim 2 , wherein the floor plate ( 11 ) has a temperature that is no higher than a few tenths of a degree Celsius above ambient temperature, substantially no more than one half degree Celsius.
11. The balance ( 1 ) according to claim 10 , wherein said temperature is a few tenths of a degree Celsius below ambient temperature, substantially no more than one half degree Celsius.
12. The balance ( 1 ) according to claim 2 , wherein the at least one thermoelectric module ( 16 ) has a hot side and a cold side and is attached to the floor plate ( 11 ) with the cold side facing towards the floor plate ( 11 ) and the hot side facing towards an outside environment of the balance.
13. The balance ( 1 ) according to claim 2 , further comprising a heat-conducting body ( 15 ) connected to the floor plate ( 11 ) and the vertical wall ( 8 ), wherein the at least one thermoelectric module ( 16 ) has a hot side and a cold side and is attached to the heat-conducting body ( 15 ) with the cold side facing towards the heat-conducting body ( 15 ) and the hot side facing towards an outside environment of the balance.
14. The balance ( 1 ) according to claim 1 , further comprising a heat sink ( 17 ) connected to a hot side of the at least one thermoelectric module ( 16 ) to provide a rapid heat removal into ambient air.
15. The balance ( 1 ) according to claim 3 , wherein the measuring cell compartment ( 9 ) comprises a weighing-cell electronics ( 20 ) module arranged in an upper half of the measuring cell compartment ( 9 ), so that a heat flow is generated from the weighing cell electronics ( 20 ) to the at least one vertical wall ( 8 ) and said heat flow enhances the temperature gradient in the stationary vertical wall.
16. The balance ( 1 ) according to claim 15 , wherein said electronics ( 20 ) module is arranged in the top third of the measuring cell compartment ( 9 ).
17. The balance ( 1 ) according to claim 1 , wherein the at least one vertical wall ( 8 ) has a material thickness that decreases in the bottom-to-top direction.
18. The balance ( 1 ) according to claim 1 , further comprising an indicating- and operating unit ( 13 ) which can be brought into thermal contact with the floor plate ( 11 ) to remove heat caused by power dissipation of the indicating- and operating unit ( 13 ).
19. The balance ( 1 ) according to claim 1 , wherein the draft shield ( 4 ) comprises a front wall ( 5 ) with a metallic frame that is connected to the floor plate ( 11 ).