Turbidity, referred to as the cloudiness of a fluid medium, is quantified by the intensity of light scattered by particles suspended in the medium. Turbidity measurements are important indicators in many industries and application as they not only influence the yield of the industrial process, but also detect factors which are detrimental to a system.   CST’s PX2+, when used in conjunction with a flow cell or transmission probe, eliminates the need for laboratory measurements and displays the turbidity on the unit’s touch screen display. Monitoring the presence or absence of scattering particles in a process assists plant managers, operators, and technicians in reducing plant upsets, shutdowns, and loss of product. CST offers both in situ probes and extractive flow cells designed for continuous, real-time turbidity monitoring.


– Continuously and accurately measures turbidity using NIR spectroscopy.
– The all-inclusive Turbidimeter comes preassembled in a waterproof NEMA4X enclosure with a dedicated sample flow cell or transmission probe outside of the enclosure.
– Easy to use software with a digital touch display allows users to view data and calibrate.
– High reliability with a typical light source lifetime of at least 5 years.
– Standard data outputs include MODBUS, 4-20mA, and USB to CST Software.
– Low cost of ownership with no routine maintenance.
– Saves time spent sampling and measuring in a lab while preventing contamination and loss of product.


  • Measurement Principle:  NIR Absorbance
  • Range: 0-2000 NTUs
  • Repeatability: ± 1% of Full Scale
  • Light Source: NIR LED
  • Detector: Silicon Photodiode
  • Display: 3.2″ Capacitive Touch Screen Display
  • Alarms: Contact Closure (60 VDC, 0.75 A max.)
  • Analog Output: 4-20 mA, isolated
  • Analog Loop Resistance: 500 ohms @ 24 VDC
  • Digital Output: USB-B, RS-485 (Modbus)
  • Power Consumption: 8.5 watts (max.)
  • Power Requirements: 24 VDC nominal  (12-48 VDC)
  • Enclosure Material: NEMA4X Anodized Aluminum
  • PX2+ Size: 2.8” H x 4.5” W x 9.5” L
  • Temperature: 5-50C
  • Weight: 3.5 lbs. (1.6kg)
  • Sample Introduction: Flow Cell or Transmission Probe
  • Process Pressure: 2000 psi max
  • Minimum Flow Rate: 100 ml/min


  • Cell Quantification
  • Polymer Feed
  • Water in Oil
  • Biomass Growth
  • Filter Efficiency
  • Phase Separation
  • Fermentation
  • Pharmaceuticals
  • Food & Beverage
  • Wastewater