Atmospheric point discharge current measurements using a temperature-compensated logarithmic current amplifier
Marlton, G., Harrison, R. G. and Nicoll, K. A. (2013) Atmospheric point discharge current measurements using a temperature-compensated logarithmic current amplifier. Review of Scientific Instruments, 84 (6). 066103. ISSN 0034-6748
To link to this article DOI: 10.1063/1.4810849
Measurements of atmospheric corona currents have been made for over 100 years to indicate the atmospheric electric field. Corona currents vary substantially, in polarity and in magnitude. The instrument described here uses a sharp point sensor connected to a temperature compensated bi-polar logarithmic current amplifier. Calibrations over a range of currents from ±10 fA to ±3 μA and across ±20 ◦C show it has an excellent logarithmic response over six orders of magnitude from 1 pA to 1 μA in both polarities for the range of atmospheric temperatures likely to be encountered in the southern UK. Comparison with atmospheric electric field measurements during disturbed weather confirms that bipolar electric fields induce corona currents of corresponding sign, with magnitudes ∼0.5 μA.