31. Using Pierre's electrometer , she discovered that uranium rays caused the air around a sample to conduct electricity. 32. Francis Ronalds delineated intensity ( voltage ) and quantity ( current ) for the gold-leaf electrometer . 33. He designed and built an electrometer which could detect the presence of energetic charged particles ( or electromagnetic waves ). 34. He also worked on electrometers , for which he invented a new design, air pumps and wrote scientific papers. 35. This equipment bears his name today as the : Shonka ionization chamber, the Shonka electrometer , and Shonka plastics. 36. For convenience of use, the vibrating reed assembly is often attached by a cable to the rest of the electrometer . 37. Valves designed for electrometer use have leakage currents as low as a few femtoamperes ( 10 " 15 amperes ). 38. It was thanks to the use of Cywinski s electrometers that the first European semiconductor-charge copying machine was developed. 39. The engraving on the right shows a slightly different form of this electrometer , using four flat plates rather than closed segments. 40. The most common use for modern electrometers is the measurement of radiation with ionization chambers, in instruments such as geiger counters.
