Vapour actuated pressure spring thermometer does not require ambient temperature compensation. Ambient temperature compensation is provided in gas or liquid expansion pressure spring thermometer by

Making the volume of thermometer bulb as large as conveniently possible

Reducing the volume of the capillary to a minimum

Reducing the volume of the receiving element to a minimum

All $\text{'}$a$\text{'},\text{'}$b$\text{'}$ & $\text{'}$c$\text{'}$