Which instrument records the maximum and minimum temperatures in a day?

• A. Max/Min Thermometer
• B. Wet/Dry Bulb Hygrometer
• C. Rain Gauge
• D. Wind Vane

Answer: (A)

Daily temperature extremes are recorded with a Max/Min Thermometer. This device is built to keep track of the highest and lowest temperatures reached over a 24-hour period. It has markers that move with temperature changes and stay in place at the extreme values, thanks to a small constriction inside the tube. As the air warms, the liquid expands and the maximum marker is set at the peak; as it cools, the minimum marker stays at the lowest point reached. Reading both markers gives the day’s maximum and minimum temperatures. Other instruments measure humidity (wet/dry bulb hygrometer), rainfall (rain gauge), or wind (wind vane), so they don’t record the daily temperature extremes.