Abstract：We found the minutevalue observing curve of the water temperature at Wuliying station in Beijing showed 24 sawtooth figures ordinarily, and confirmed that was caused by the radon observation. We separated the radon and the electric supply for the water temperature and added an inductor between the earth wire and earth mat to cut the other jamping signals from the earth wire to the observing instrument. After the transformation, the pulse jamping of the water temperature disappeared completly and the observing quality made much improvement.
