1. Use a level: This is one of the most common and direct methods. Use the level meters in the upper and lower wells respectively, and judge the height difference by measuring the levelness of the two positions.
2. Use laser levels: laser levels is a high-precision measuring instrument, which can quickly measure the height difference of the water level. Put the laser levels in the position of the upper and lower wells, and determine the height difference through the display on the measuring instrument.