A gas thermometer is constructed
of two gas-containing
bulbs, each in a water bath, as
shown in Fig. 18-29. The pressure
difference between the two bulbs is
measured by a mercury manometer
as shown. Appropriate reservoirs,
not shown in the diagram,
maintain constant gas volume in the two bulbs.There is no difference
in pressure when both baths are at the triple point of water.
The pressure difference is 120 torr when one bath is at the triple
point and the other is at the boiling point of water. It is 90.0 torr
when one bath is at the triple point and the other is at an unknown
temperature to be measured.What is the unknown temperature?
sec. 18-5 The Celsius and Fahrenheit Scales
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