Dual Chamber Metrology Furnaces.
ITL-M-17707: Metrology Furnace for Indium and Tin Fixed-Point Cells.
ITL-M-17706: Metrology Furnace for Zinc, Aluminum and Silver Fixed-Point Cells.
ITL-M-17705: Metrology Furnace for Aluminum, Silver and Copper Fixed-Point Cells.
Using standard platinum resistance thermometers presents many problems due to strain and contamination, which can too easily be introduced into the thermometer during thermal cycling. 156.5985°C.
Because such problems have been only partially understood, little published information or equipment is
available for the safe-handling of these sophisticated devices.
Dual Chamber Metrology Furnace
| Model | Description | Price |
|---|---|---|
| ITL-M-17707 | Metrology Furnace for Indium and Tin Fixed-Point Cells | Call |
| ITL-M-17706 | Metrology Furnace for Zinc, Aluminum and Silver Fixed-Point Cells | |
| ITL-M-17705 | Metrology Furnace for Aluminum, Silver and Copper Fixed-Point Cells |
We feel that enough information exists for us to propose a new apparatus specifically designed, not only to create and maintain the Fixed Points of ITS-90, but also to pre- and post-condition the thermometers to be calibrated.
Thus, in our dual-metrology furnaces, we have incorporated a second furnace which, because of its unique design, will safely (and without contamination) pre- and post-condition the thermometers.
Method of operation
The fixed-point cell is melted in an essentially gradient-free heat-pipe.
When melting is complete, the heat-pipe temperature is readjusted to be 0.5°C below the freeze
temperature of the cell.
A cold rod introduced into the cell’s reentrant tube initiates the freeze, to give a plateau that will last between 12 and 24 hours.
The thermometers are removed from their storage rack and placed in the pre-conditioning furnace.
The furnace is slowly heated to the Cell temperature. The thermometers are protected from contamination by a slow air flux around them.
One by one the thermometers are transferred into the cell for 20 to 30 minutes for calibration and then
back to the conditioning furnace.
When all the thermometers have been calibrated, the conditioning furnace is slowly cooled back to
400°C where the thermometers can safely be removed into room temperature.
When melting is complete, the heat-pipe temperature is readjusted to be 0.5°C below the freeze
temperature of the cell.
A cold rod introduced into the cell’s reentrant tube initiates the freeze, to give a plateau that will last between 12 and 24 hours.
The thermometers are removed from their storage rack and placed in the pre-conditioning furnace.
The furnace is slowly heated to the Cell temperature. The thermometers are protected from contamination by a slow air flux around them.
One by one the thermometers are transferred into the cell for 20 to 30 minutes for calibration and then
back to the conditioning furnace.
When all the thermometers have been calibrated, the conditioning furnace is slowly cooled back to
400°C where the thermometers can safely be removed into room temperature.
Dual Chamber Metrology Furnaces.
| MODEL | ITL-M-17707: for Indium and Tin Fixed-Point Cells
ITL-M-17706: for Zinc, Aluminum and Silver Fixed-Point Cells ITL-M-17705: for Aluminum, Silver and Copper Fixed-Point Cells |
| Dimensions | 960mm x 600mm x 560mm (HxWxD) |
| Control | The heat-pipe and the thermometer conditioning furnaces
are controlled independently to a resolution of 0.1°C |
| Communications | Included as standard |
| Over-Temperature Protection | Provided on each furnace with independent sensor |
| Supply | 110 VAC ±
10% (50 / 60Hz) |