How useful are thermometers if they only show their temperature?

[gdpudasaini]

Thermometer are useless because it shows its own reading? Please someone answer me how.

 

[f95toli]

I am not sure I understand you question.
Are you asking how we calibrate thermometers?
I.e. how to relate what a thermometer shows to the thermodynamic temperature.

 

[Danger]

Yeah, it's a badly worded question. Are you suggesting that the thermometer reads only its own temperature? If so, then you are correct; but... its own temperature is determined by its environment, so it gives an accurate account of what it's measuring.

 

[FredGarvin]

Any instrument can be useless. It all depends on their proper usage and calibration. Thermometers are obviously not useless when used within their devised usage. Again, please restate your question.

 

[TVP45]

Thermometers are designed to quickly achieve thermal equilibrium with their surroundings, thus reading the temperature of the surrounding.