minimum thermometer
A thermometer that records the lowest temperature reached over a period, used in meteorology and cold-chain monitoring.
In meteorological observation, a minimum thermometer is used to record the day's lowest temperature.
Records the highest temperature, while 最低温度計 records the lowest.
General term for thermometer; 最低温度計 is a specific type.
Compound of 最低 (lowest) + 温度 (temperature) + 計 (meter).