DI Water Particle Counter: Ultra DI® 50

Sensitivity range: 0.05 – 0.2 µm

The Ultra DI® 50 Liquid Particle Counter is designed specifically for de-ionized (DI) water systems and will count and size contaminants as small as 0.05 μmLarger sample volumes and ultra-low zero counts detect smaller excursions with more relevant statistical data, while shorter sample intervals speed up your analysis time. Respond immediately to contamination with real-time measurement of particles, and Save time with fast clean-up and the ability to move quickly from one sample point to another. Its low zero count, large sample volume and high counting efficiency provide unsurpassed performance.

Looking for industry leading 20 nm particle counting?
See the Ultra DI 20 particle counter.

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Compare and choose from the complete line of liquid particle counters from Particle Measuring Systems.

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PMS Ultra DI 50
PMS Ultra DI 50 front
PMS Ultra DI 50 back


  • Reliable Liquid Particle Counter
  • Low zero count
  • Large sample volume
  • Faster time to statisitically significant data
  • Compatible with FacilityNet Software
  • Utilizes existing network with ethernet communication
  • Connects directly to PLC and SCADA systems with 4-20 mA
  • Compatible with ozonated water
  • Stainless steel housing and dual HEPA filtration allow use in dirty environments


  • FacilityNet Software provides more sophisticated process control
  • Set tighter process control limits with low sample-to-sample variation
  • Detect process variations more quickly with improved sensitivity


  • Quantifying particle concentration in state-of-the-art ultra pure water (UPW) systems
  • Filter efficiency measurements
  • Trending analysis at lower particle concentrations
  • Detecting bacterial growth in UPW systems
  • Episodic event tracking and alarming
  • Continuous system monitoring
  • Manufacturing process control

Supporting Materials

Specification Sheets

Ultra DI® 20 Liquid Optical Particle Counter >

Ultra DI® 50 Liquid Optical Particle Counter >

Application Notes & Brochures

Which Ultrapure Water Particle Counter is Best for Your Application? >

Particle Monitoring Strategies in UPW: 300 mm Fabs >

Statistics of Particle Counting in Ultrapure Water >


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Available Accessories

Facility Net

Facility Net

Facility Net Software provides a solution for comprehensive environmental monitoring, including a real-time and historical data display. Compatible with Particle Measuring Systems particle counters and molecular contamination monitors, as well as various third-party products.

Liquid Installation Kit

Liquid Installation Kit

For use with online  applications, the Liquid Installation Kit includes: a Flaretek® flaring tool, five caps, 25 ft of 1/4 in Perfluoroalkoxy alkanes (PFA) tubing and male connectors.

Capillary Cleaning Kit

Capillary Cleaning Kit

The Capillary Cleaning Kit flushes capillaries with a Flaretek® adapter and contains: two 10cc syringes and two Flaretek® tube fittings.

FC-100 FC-200

Downstream Flow Controller

Complete flow control through a liquid particle counter is critical to ensure accurate and actionable data. The Downstream Flow Controllers, FC-200 and FC-100, are the perfect complement to our high precision liquid particle counters.