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Condensation Particle Counter


For safe operation, an external fuse must be inserted before the CPC is used. This should be just a low voltage fuse for the battery within the CPC.

When the machine is first switched on, the date and time will appear. The machine will then ask whether you wish to initiate warm-up. The warm-up procedure will start automatically soon after the machine is switched on if no instructions are given. The settings of the instrument for any particular reading may be controlled and set using the Windows software program.

Attach the reservoir to the appropriate port to collect condensation from the condensor.

A green LED at the rear of the device displays the butanol level. To top up the butanol level, attach the external refill bottle and remove the cap. Make sure the CPC is in Standby mode.

To switch to Dryer mode from Charge mode, press set-up and standby. Pressing 'Alt 1 2 4' in the Windows software will put the instrument into Service mode. Further information will then be offered with each command given BUT the instrument will not register errors in this mode and so will continue taking readings even if there is a problem e.g. no butanol. To return to the normal operation mode, press'Alt 1 2 4' again.


Raw data is outputted from the instrument and recorded in a measurement file.

'Scans' can be completed which involve very small repeating steps. The voltage steps of the scan are dependent on the DMA.

Scans can only be completed over a 300 second period.

Every other bin in a scan may be skipped in order to reduce the amount of time taken for the scan - these values are instead calculated by the software.

For further information on the scanning methods see Colin, Flagan et al. (2001).


The instrument will NOT work if :

  • the optic is dirty
  • The droplets are growing to different sizes
  • the flow rate is wrong
  • the butanol is diluted or there is not enough etc.

The internal battery will last only 4-5 hours but this is dependent on conditions.

The instrument is able to count up to 1e10 particles per ccm and the data is displayed in counts per ccm. It can measure particles in the size range 5nm-350nm in 44 channels.

The SMPS+C is not designed to be operated when the ambient temperature is greater than 30C. There is a separate adapter for high temperature use but this requires more energy.

Earth Observation Data Group, Department of Physics, University of Oxford. Page last updated: @21:11 GMT 13-Apr-2014