Can there be any error in the reading of spring dynamometer in Zhengzhou Physics and Chemistry Laboratory?

Yes. According to the relevant information, there is an error when it is unstable. If the spring is above the stable position, the spring is in a contracted state, and the read value is smaller than the actual value of the measured object. The reading of the spring dynamometer starts from the 0 scale, and each small division is 0.2N. Count how many divisions the pointer points to, and then multiply the number of divisions by 0.2.