Ein Patent, was meint, damit auf 0.01°C genau eichen zu können:
https://patents.google.com/patent/US6530280B2/en
Hier ein professionelles Hypsometer zur Kalibrierung:
https://units.imamu.edu.sa/colleges/en/ ... h1_web.pdf
Hier S. 16 (26 von 136)
https://nvlpubs.nist.gov/nistpubs/Legac ... 250-23.pdf
4.2.2 Steam Bath
Although the ice point at 0 °C is most often the reference point, the steam
point at 100 °C is sometimes used. The steam bath or hypsometer used at
NBS and its schematic drawing are shown as Figures 7 and 8, respectively.
This bath is used only if the 100 °C mark is too close (less than 50 mm) to
the bulb or contraction chamber to permit adequate immersion of these large
volumes of mercury in an oil bath. Approximately 1,000 ml of distilled
water is placed in the boiler. A Fisher burner is ignited under the boiler
and in approximately one hour the bath is ready to be used.
Steam produced from the boiler circulates within a double-walled steam
jacket permitting free circulation of steam around the thermometers
suspended within this space. Water condenses and drips from the
thermometer. A provision is made both for relieving any excess pressure in
the space surrounding the thermometers and for determining the excess
pressure by means of a small differential manometer.
When the steam bath is used as a comparison bath, the temperature of the
steam is determined at the time of test with a standard platinum resistance
thermometer.
The steam bath can also be used as a fixed-point apparatus. In this case a
barometer is used, since the temperature of the steam depends on the
prevailing atmospheric pressure. The usual adjustments must be made to the
barometer reading, including any necessary corrections for the value of
local acceleration of gravity, for the difference in height between the
steam bath and the barometer, and for any excess pressure above atmospheric
in the steam jacket. After the corrected pressure reading is obtained, the
temperature of the steam can be derived from the values given in Table 2.
Also hier wird das Gerät mit Reflux betrieben.
Hier auf S. 242 (245 von 536):
https://nvlpubs.nist.gov/nistpubs/Legac ... n300v2.pdf
The steam point as realized
by utilizing the condensing vapor in a hypsometer
is certainly accurate to 0.01° C. An accuracy
of about 1° C can be obtained by merely
immersing a thermocouple in boiling water.
Was ich nicht verstehe, ist, warum oft vom "condensing vapor" gesprochen wird.