The accuracy of the power frequency electric field measurement results in power transmission and trans-formation projectis of great importance to environmental evaluation of power engineering. However

we have foundthat high environmental humidity could lead to larger power frequency electric field intensity measurement results.In order to verify the accuracy of the measuring device and investigate the effects of environmental humidity on thepower frequency electric field intensity measurement results and improvement method

two ways of sealing and sus-pension of the sensor are applied in standard electric field. The effects of the environmental humidity on the measure-ment results of power frequency electric field intensity are investigated. The range of the environmental humiditywhich can affect test results is obtained

and the solution of improving the testing accuracy is given on the power fre-quency electric field intensity measuring for calibration or comparison experiment of equipment in laboratory. The re-sults demonstrate that suspension of sensor and bringing down environmental humidity below 55% could reduce theeffects of environmental humidity on measurement accuracy effectively. This study is of great significance in improv-ing power frequency electric field intensity measuring method in power transmission and transformation project

alsoit is meaningful to promote the revision of relevant standards.