Gas Thermometer. Not dependent on gas?

PFCalvin

Hello Guys!
I was wondering if anyone can tell me why is it that it doesn't matter what gas we are using in the gas thermometer? Will it still be standardized for calibration if we use different gases?

Thanks.

PFCalvin

Yes?

Dadface

The gas thermometer calculates temperature by use of the ideal gas equation but whatever the gas used it must be real and not ideal.A series of pressure readings are taken at gradually reducing pressures and these can be used to extrapolate and find out what the calculated temperature approaches as the pressure appproaches zero.The clever thing is that all gases approach ideal behaviour as the pressure approaches zero.If I remember correctly any other deviations from ideal behaviour are accounted for by taking into account the characteristics of the gas used.

PFCalvin

What do you mean when you say that "... gas used it must be real and not ideal"?

Dadface

All gases are real gases and, for example ,do not obey Boyles law exactly.Gases,however, become more ideal in their behaviour as the gas pressure tends to zero and provided that other conditions are met.