Model
17724 Mercury Triple Point Cell and Model 17725 Mercury Triple Point Apparatus.
17724 Mercury Triple Point Cell will realize the mercury triple point (-38.8344°C)
from either the freeze or the melt approach, within 0.0005°C of the ITS-90 value. |
|
Mercury Triple Point Temperature Standard
The
Apparatus is a free-standing, mechanically refrigerated cryostat. The cell is placed
in its well, which is operated in the form of an essentially gradient-free heat pipe.
A unique control system provides a precise means for regulation of the cell and
well temperature over the range from -36°C to -42°C, allowing the mercury triple
point to be approached optionally from the freezing or melting direction. Two
auxiliary wells are pre-chilling thermometers to be calibrated. The cell containment
is a plasma-arc welded stainless steel shell. The mercury contained has impurities
of less than 15 parts per billion. The purity of the metals such that triple point
plateaux are flat to 100 microkelvins (0.0001°C)
- Free standing, self contained, precise control system
- Calibrates at -38.8344°C
|
