Overview: LiQuilaz® II E-Series Liquid Particle Counters

The LiQuilaz® II E-Series from Particle Measuring Systems is designed for volumetric particle counting in high-purity liquids. The series supports pharmaceutical water, medical-device, parenteral-solution, filtration, and precision-cleaning applications where reliable particle-size distribution data is required. Instead of observing only a fraction of the liquid stream, the instrument measures 100% of the sample volume that passes through its sensing zone. This approach is especially useful when particle concentrations are low or the available sample volume is limited.

Across the E-Series, the combined measurement range extends from 1.5 to 125 µm, with up to 15 user-adjustable size channels. Model selection depends on the required minimum particle size, nominal flow rate, and sampling architecture. The E15P configuration starts at 1.5 µm and operates at a nominal 20 mL/min. The E20 covers 2 to 125 µm at 70 mL/min and is generally suited to online or process-point monitoring. The E20P covers 2 to 125 µm at 20 mL/min and is commonly paired with a precision syringe sampler, including the APSS-2000 system used for controlled laboratory sampling.

A syringe sampler uses a precision syringe to draw and dispense a defined liquid volume through the particle counter. In Vietnamese, this article translates “syringe sampler” as “bộ lấy mẫu bằng xi lanh định lượng.” This arrangement helps control sample volume and minimize liquid waste. It is useful for container samples, pharmaceutical testing, and other applications where continuous online installation is not practical. By contrast, an online E20 installation can provide faster visibility into process changes, filtration events, maintenance effects, or contamination excursions.

Published E-Series technical information lists a recommended maximum concentration of 10,000 particles/mL, sample temperatures from 10 to 50 °C, a maximum sample pressure of 200 psi, and background counts below 50 particles/L. Wetted materials include fused silica, black quartz, PTFE, Kel-F, and Kalrez. These values are useful for preliminary selection, but chemical compatibility must be confirmed for every liquid. Bubbles, unstable flow, dirty tubing, unsuitable valves, or residues from previous samples can all affect particle results and should be controlled through a documented sampling procedure.

LiQuilaz II instruments support RS-485 and Ethernet communication and can be integrated with PMS software platforms. FacilityNet or FacilityPro may be considered for process monitoring, while SamplerSight and SamplerSight Pharma support controlled sample testing and reporting configurations. Compliance with 21 CFR Part 11 should always be evaluated at the complete system level. A particle sensor alone does not establish compliance; software security, audit trails, user access, validation, procedures, and data governance must work together.

Users should also distinguish current LiQuilaz II instruments from older non-RoHS LiQuilaz models addressed by a 2017 PMS obsolescence notice. LiQuilaz II is the replacement generation and adds Ethernet connectivity and RoHS compliance while maintaining the intended measurement performance. For an installed legacy unit, the exact model, part number, and serial number should be reviewed before planning calibration, repair, or replacement.

SAO NAM supports customers in Vietnam with application review, configuration selection, installation planning, calibration, technical inspection, and service coordination for Particle Measuring Systems equipment. Before requesting a quotation, prepare the liquid name and composition, target particle sizes, sample volume, viscosity, pressure, temperature, flow conditions, data requirements, and applicable quality standards. This information helps determine whether E15P, E20, E20P, a syringe-sampling configuration, or a complete APSS-2000 system is the most appropriate solution.