Why and how to adjust after reading the highest and lowest thermometers?

Observe at 20 o'clock every day, record the reading in the corresponding column of the observation book, and adjust the thermometer after observation. Meteorological offices and stations that send weather reports or encrypted weather reports shall make supplementary observations in accordance with the provisions of the specifications, and must make adjustments after observation. When observing the lowest temperature indicator, the eyes should aim at the far end of the cursor away from the sensing part; When observing the indicator of alcohol column, the eyes should be straight to the midpoint (i.e. the lowest point) of the concave surface at the top of alcohol. When the alcohol column of the lowest thermometer (including the lowest thermometer on the ground) is interrupted in the observation reading, the lowest temperature record shall be treated as missing measurement and indicated in the remarks column of the observation book; Watches must be repaired or replaced in time. Because it records the highest and lowest temperatures in the air for a period of time, it needs to be adjusted if it is to be re-measured.

Adjustment: Raise the sensing part of the thermometer, tilt the body and return the cursor to the top of the alcohol column.