Among the following, standard temperature can be measured by

In gas thermometers, Hydrogen is used as thermometric substances. The

change of pressure at constant volume of hydrogen at ordinary temperature

is uniform than any gas. So this thermometer is used to measure standard

temperature.

Note:-

(a)Mercury expands up to$356°C$

(b)Pyrometer measures temperature of sun at which non uniform heat is

generated.

(c)Thermo electric thermometers measure non uniform temperatures