A flow-through electrode unit for measurement of particulate atmospheric nitrate

Abstract

The design and performance of a flow-through electrode unit for use in the measurement of particulate atmospheric nitrate is described. The unit, housing ion-selective nitrate indicator and fluoride reference electrodes, provides temperature control (± 0·5 °C), a sensitive regulation of solution content (44 ± 1·5 ml) and optimum liquid circulation, while minimising liquid volume. Preliminary tests conducted at 38·5 ± 0·5 °C indicate that the unit behaves as an ideal well stirred vessel with a time constant τ=V/Q.