This page provides an overview of the GRIMM SMPS+C aerosol measuring equipment.
The Sequential Mobility Particle Sizer + Counter (SMPS+C) is designed to make measurements of particles in the size range of ~5nm to 30 micrometres. It consists of two parts: the Differential Mobility Analyser (DMA) and the Condensation Particle Counter (CPC).
The DMA differentiates particles by their electrical mobility and is based on the principle of electrostatic classification. Aerosol particles pass between electrodes in the DMA and are subject to an electric field. These particles will all have different electrical mobilities and this allows the DMA to separate the particles. Aerosol particles within a certain size range are removed and passed on to the CPC. Since the voltage size will determine the size range of particles selected, the DMA may be used to produce a monodisperse aerosol of specific size.
Contents of DMA Manual:
The CPC is used to find the concentrations of particles that are too small to be counted by usual light scattering mechanisms. It works in real time by the principle of nucleous condensation. Liquid vapour condenses onto the small aerosol particles and these scatter light that is then measured. Butanol is used as it is more efficient to use this than water. The CPC may be battery operated if required and has a port for the attachment of external analogue sensors. It may also be remotely operated via a modem and has a data storage card for fieldwork.
Contents of CPC Manual: