Huiron HRH-NEU85 Aerosol Electrostatic Neutralizer

Overview

The Huiron HRH-NEU85 Aerosol Electrostatic Neutralizer is an engineered component for precision aerosol metrology and inhalation toxicology systems. It operates on the principle of corona discharge ionization—generating balanced bipolar ions from clean, dry compressed air without reliance on radioactive sources (e.g., ⁸⁵Kr or ²¹⁰Po). This enables safe, regulatory-compliant integration into GLP- and ISO 17025-aligned laboratories, particularly where radioactive material handling restrictions apply. The device facilitates charge equilibration of polydisperse aerosol populations to Boltzmann equilibrium, a prerequisite for accurate size classification using differential mobility analyzers (DMAs), scanning mobility particle sizers (SMPS), and electrostatic precipitators. Its design targets reproducible neutralization across variable aerosol concentrations and flow regimes, supporting traceable calibration of aerosol instrumentation per ISO 27891 and ASTM D8196 guidelines.

Key Features

• Corona-based bipolar ion generation—eliminates need for licensed radioactive sources and associated disposal protocols
• Adjustable volumetric flow range (5–50 L/min) with stable ion output across operational pressure window (0.05–0.7 MPa)
• High charge balance performance: residual particle potential ≤ ±10 V after neutralization, verified via Faraday cup electrometer measurement
• Modular mechanical interface—designed for OEM integration into exposure chambers, aerosol generation trains, and real-time monitoring platforms
• Robust thermal management ensures consistent ion yield under ambient conditions from 0–55 °C and 35–65 % RH
• CE-marked power supply (220 V AC, 50 Hz) with internal overvoltage and current-limiting protection

Sample Compatibility & Compliance

The HRH-NEU85 is compatible with liquid, solid, and combustion-generated aerosols—including NaCl, DEHS, ammonium sulfate, carbon black, and bioaerosol surrogates—provided carrier gas dew point remains below −40 °C to prevent ion recombination. It meets electromagnetic compatibility (EMC) requirements per IEC 61326-1 and electrical safety standards per IEC 61010-1. As a non-radioactive neutralizer, it aligns with national regulations governing radiation-free laboratory instrumentation (e.g., China’s GBZ 128-2019 and EU Directive 2013/59/Euratom exemptions for exempt devices). For inhalation studies conducted under OECD Test Guidelines 412 or 413, the unit supports compliance with particle charge control stipulations in Annex IV of ISO 10993-12.

Software & Data Management

While the HRH-NEU85 operates as a standalone hardware module without embedded firmware or digital interface, its analog-compatible design allows seamless integration with programmable logic controllers (PLCs) and data acquisition systems (e.g., National Instruments DAQmx or LabVIEW environments). Users may log inlet/outlet pressure differentials, flow rate (via external mass flow meter), and ambient temperature/humidity via third-party sensors for audit-ready system validation. When deployed in FDA-regulated inhalation toxicology workflows, the neutralizer supports 21 CFR Part 11-compliant electronic records when paired with validated SCADA platforms that enforce user authentication, audit trails, and electronic signatures.

Applications

• Primary calibration of scanning mobility particle sizers (SMPS) and differential mobility analyzers (DMA)
• Charge conditioning upstream of cascade impactors (e.g., Andersen, MOUDI) to minimize electrostatic deposition artifacts
• Pre-conditioning of test aerosols in OECD-compliant subchronic and chronic inhalation exposure studies
• Reference-grade neutralization in NIST-traceable aerosol reference material production
• Supporting ISO 16890 filter testing by ensuring standardized charge state prior to fractional efficiency measurement
• Enabling quantitative nanoparticle dosimetry in vitro using air–liquid interface (ALI) exposure systems

FAQ

Does the HRH-NEU85 require radioactive source licensing or special disposal procedures?
No. It uses corona discharge exclusively and contains no radioactive isotopes.
Can it be used with humidified aerosol streams?
No. Inlet air must be clean and dry (dew point ≤ −40 °C); elevated humidity accelerates ion recombination and degrades neutralization efficiency.
What is the recommended maintenance interval?
Inspection and cleaning of the corona electrode assembly every 500 operating hours; replacement of the inlet particulate filter every 200 hours under continuous operation.
Is flow rate linearly correlated with neutralization efficiency?
Within the 5–50 L/min range, neutralization efficacy remains stable above 95% of Boltzmann equilibrium when operated within specified pressure and dryness limits.
How is charge balance verified during qualification?
Using a calibrated Faraday cup electrometer and monodisperse PSL particles (e.g., 100 nm, 300 nm) at defined flow rates—per ISO 27891 Annex B protocols.