利用宁波地震台水温10年来的单测项、6年来的同层比测资料，对高精度温度计的仪器短期和长期稳定性进行分析对比。研究发现仪器长期存在漂移现象，漂移量的大小与每套仪器的系统特性有关，但随着观测时间的延续，漂移量逐渐减少，认为该现象对地震前兆观测影响不大；短期稳定性存在不明原因的阶跃和脉冲现象，但次数不多，幅度不大，如果不是并行观测，较难判别。因此，在资料分析时要考虑仪器的这些问题。有时仪器短期非常稳定，数天至20天整点值为同一测值。

Based on the 10 year single observation item Ningbo seismic station water temperature and the 6 year same level comparing test data,we compared and analzed the short-term and long-term instrumental stability of the high precision thermometer. It is found that the instrument has long drift phenomenon,and each instrument drift amount is linked to the instrument characteristics,but with the continuation of observation time,drift amount gradually reduces and the phenomenon has little influence on the seismic precursory observation. Unknown steps and pulse phenomena exist in the short term stability,but the frequency and the amplitude are not large,and are difficult to determine if not in parallel observation. Therefore,these problems should be taken into account in the instrument data analysis. Sometimes short-term instruments are very stable,the whole point will remain at the same value for several days or even 20 days.

P315

中国地震局地震前兆台网数字化改造项目（95-01-02）和浙江省地震局"十五"改造项目共同资助