20 nm Liquid Particle Counter: Ultra DI® 20 Plus

Sensitivity range: 20 – 100 nm

Designed specifically for ultrapure water systems, the Ultra DI® 20 Liquid Particle Counter from Particle Measuring Systems PMS quickly obtains statistically meaningful data and will count and size contaminants as small as 20 nm. Consistency helps you get more out of your data, even if the instrument moves, so you have more control over your process. The Ultra DI 20 Liquid Particle Counter has a low zero count, large sample volume and high counting efficiency that provides benchmark particle detection. Improved sensitivity allows you to detect process variations more quickly with 20 nm polystyrene latex (PSL) and 9 nm gold (Au).
The UDI-20 is one of Particle Measuring Systems’ “Industry Leading Sensitivity” products. This means that there are no products on the market that are more sensitive than these and only PMS offers a line of products covering this many elements of production monitoring. PMS currently leads the market in monitoring performance, sensitivity and reliability in the Ultrapure Water, Chemical and Airborne Molecular Contamination Monitoring fields. PMS’ superior knowledge, technology and service provides High Tech and Chemical manufacturing companies with the most advanced tools to make accurate data-driven decisions, improving both performance and yield.


  • New design eliminates the additional purchase price and maintenance cost for an environmental enclosure
  • Respond immediately to contamination with real-time particle measurement
  • Quickly obtain meaningful statistical data to detect particle excursions and troubleshoot problems
  • Fast sample cleanup shortens the time to move from one sample point to another
  • Speed up analysis time by using shorter sample intervals
  • FacilityNet Software provides more sophisticated process control
  • Set tighter process control limits with low sample-to-sample variation


  • Advanced laser optics and sensors enable detection of particles down to 20 nm (9 nm Au)
  • Unmatched instrument to instrument data stability and matching with thermally stabilized measurements of particles across an 18 to 29°C operating environment
  • Instrument to instrument matching within 20% at concentrations of < 10 particles per ml
  • Compare UPW system performance across multiple fabs in any environmental conditions anywhere in the world
  • Fleet can be swapped without disruptions or questions about the data
  • Two counting modes: 1) High resolution – for pure environments 2) High concentration – for filter challenge tests and lower purity environments
  • Connect directly to PLC and SCADA systems with 4-20 mA and utilize existing network with Ethernet communication
  • Local particle counter data display
  • Larger particle counter sample volumes and ultra-low zero counts detect smaller excursions with more relevant statistical data
  • Uses existing network with ethernet communication
  • Connects directly to PLC and SCADA systems with 4-20mA
  • Compatible with ozonated water
  • Stainless steel housing and dual HEPA filtration for use in clean environments

Additional information

Product Type





Ultrapure Water / DI Water

Smallest Particle Size


Supporting Materials