江南霉雨天气,大气的相对湿度常在98%以上。用应变片进行应变测试时,即使对应变片采取防潮措施,也往往不能保证其绝缘电阻在50兆欧以上。八○年五月至六月间,我们对桂林橡胶机械厂55时双模定型硫化机进行产品定型校核测试时,虽然我们用石蜡、松香、黄油的混合防潮涂料对应变片进行防潮保护处理,但仍遇到应变片绝缘电阻严重下降的问题, Jiangnan mildew weather, the relative humidity of the atmosphere often more than 98%. Strain gauge strain test, even if the strain gauge to take measures to prevent moisture, but also often can not guarantee that the insulation resistance of 50 megohms or more. From May to June of 1980, when we finished the product type checking test on the 55-hour dual-mode vulcanizing machine of Guilin Rubber Machinery Factory, although we used the mixed moisture-proof paint of paraffin, rosin and butter to dampproof the strain gage , But still encounter the serious problem of strain gauge insulation resistance decline,