TSI 3789 Versatile Water-Based Condensation Particle Counter


Water-based CPCs deliver accurate concentrations of particles in gases while making use of safe, eco-friendly and easily available distilled water. When combined with a particle sizer, nanoparticle size distributions and concentration can be quantified from <2 nm to nearly 1,000 nm.

The third generation of water-based CPC comes with numerous enhancements:


  • Unprecedented reliability
  • Low maintenance
  • Adjustable counting efficiency
SKU: TSI3789 Tags: , , ,



  • Selectable counting efficiencies
  • Predefined setpoints of 50% counting efficiency for 2.2 nm and 7 nm (sucrose)
  • Custom setting memory for user-defined counting efficiency
  • Single particle counting up to 2 x 105 particles/cm³
  • Distilled water as convenient, eco-friendly and safe working fluid
  • 50 Hz data acquisition
  • Built-in SMPS™ spectrometer compatibility
  • Large internal memory for 1+ year of data
  • Remote control and data download through Ethernet


  • Particle formation and growth studies
  • Nanotechnology research or process monitoring
  • Inhalation or exposure chamber studies
  • Long-term, uninterrupted air quality monitoring

Product Details


This product was presented at the International Aerosol Conference in the form of an operational prototype. Specifications are subject to change until final release. Request a quote to be kept up-to-date with newest information.


Unprecedented Reliability – RESISTANT TO FLOODING


Rely on constant operation of the W-CPC under many different conditions. The third generation of W-CPC from TSI is robust by design:


  • Micro-pumps control the water injection into the wick and the ejection of excess water from the wick. Controlling both of these flows prevents the accumulation of excess water inside the instrument, even in the case of a blocked inlet.
  • The condensation process has been extended by a third step. Following the inlet:


  1. The aerosol is conditioned in a cooled, humid environment
  2. Heat forces water vapor to supersaturate in the centerline of the flowpath, and initiates condensation on the nanoparticles
  3. Cooling down, the condensation process is concluded. Excess water vapor is condensed, preventing water condensation in subsequent parts of the instrument. This condensed water flows back into the lower portions of the wick for reuse


All three stages are connected by a single newly designed wick which serves as the water reservoir.


These features make the new Versatile Water-based CPC very resistant to pressure changes occurring in some experimental setups. The following stress test shows that the 3789 recovers rapidly from extreme and frequent pressure fluctuations, returning quickly to making accurate measurements. In the test, the CPC inlet was temporarily blocked over 1,000 times, simulating extreme pressure fluctuations. The concentration readings dropped during the blockage of the sampling flow as expected. After the blockage was removed the concentrations recovered quickly to the same level as the undisturbed reference CPC.


Low Maintenance – LONG WICK LIFETIME


While the wick serves as the water reservoir, a stagnant reservoir can quickly become contaminated with microbial growth. This degrades the wick and compromises data quality. To resolve this problem, the design of the 3789 uses a slight amount of excess water to flush the wick. This regenerates the wick material and extends the wick life-time to 6 months of operation time and beyond.


Adjustable Counting Efficiency – NEW FLEXIBILITY


New to CPC technology is the ability of the 3789 to enable the user to easily vary the counting efficiency of the instrument. The user interface provides the choice of setting the 50% counting efficiency to 2.2 nm, 7 nm, or to a custom setting. The pre-defined efficiency setpoints are valid for sucrose and characterised at TSI.


For the first time, the skilled researcher can choose different setpoints, characterize the counting efficiency curve with appropriate instrumentation, and the 3789 will save the chosen settings as custom setpoints.