Abstract: A kind of automatic quantitative degassing device, which is suitable for automatic gas observation instrument and applied in the seismic groundwater precursor digital observation, is introduced in this paper.This device is designed based on the method of gas solution balance.The cross-linked bi-circulating technology is used and mono-plate processor controls the program of this device.The continuously measured water sample, which flows through the device, is used to periodically prepare quantitative volume gaseous sample which concentration is definitely relative to the measured water sample.The gaseous sample is furthermore measured by automatic gas observation instrument, and the real concentration of the solution gas of measured water sample is accurately given based on the theoretical formula.Furthermore the “regulated voltage function” and “dewater function” are specially designed to make the working performance of this device more stable.

Key words: Seismic precursor, Groundwater solution, Degassing device