title: A simple electrometer--ratiometer of high sensitivity and precision.
mesh_terms: D000669:Amplifiers, Electronic; D004560:Electricity / Q000295:instrumentation*; D005720:Gamma Rays; D005740:Gases; D007477:Ions; D011199:Potentiometry; D014965:X-Rays
chemical_list: D005740:Gases; D007477:Ions