Six condensation particle counters for ambient DMPS measurements and total concentration measurements

Institute for Atmospheric and Earth System Research of the University of Helsinki invites tenders for six condensation particle counters for ambient DMPS measurements and total concentration measurements.

Institute for Atmospheric and Earth System Research of the University of Helsinki invites tenders for six condensation particle counters for ambient DMPS measurements and total concentration measurements. Minimum requirements for the devices: • Sub-ten nanometer detection threshold Dp50% • Operating fluid n-butanol or similar. Fluid must be such that particle chemical composition does not have a significant effect for the instrument detection threshold • Concentration range 0.01-100000 1/cm3 with 10% accuracy or better without need of calibration, just coincidence correction • Fast response, T95% less than three seconds • Robust operation, must work on high humidity • Stable flow rate. Aerosol flow rate must be easily measured with an external flow meter. Aerosol flow rate must be more than 0.3LPM due to low concentration counting statistics issues • Must work more than two weeks without maintenance • Wide temperature range 10-35 degC • Data output through serial port and pulse concentration output (one TTL pulse per detected particle). All data and instrument status values must be available via serial port. • Operating software must work in Windows 10 64bit operating system