electroscope

名词 electroscope:

1. measuring instrument that detects electric charge; two gold leaves diverge owing to repulsion of charges with like sign

e.lec.tro.scope

n.（名词）
An instrument used to detect the presence, sign, and in some configurations the magnitude of an electric charge by the mutual attraction or repulsion of metal foils or pith balls.
验电器：用于如下目的的一种仪器：检验物体是否带电，指示物体是否带电，通过金箔条或木球的互相吸引或排斥测量电荷的强度

【引伸】
elec.troscop.ic