The main types

A mini thermo-hygrometer is a small, portable form. A remote thermo-hygrometer has a sensor that sits away from the display. A thermo-hygrometer with min-max memory keeps the highest and lowest readings since it was last reset. A baro thermo-hygrometer adds air pressure to the same display.

Specialist terms

A digital sling psychrometer thermo-hygrometer is a specialist instrument name that appears in search for this family; it is a different instrument design, not a variant of the household meter. A general thermo-hygrometer is the plain form, with no specialisation.

What to confirm

Ask about range, accuracy, display readability and power source. Those figures are not stated on this site; a buyer who needs a particular range should name it in the inquiry.