SMACH RN200 Neutron Ambient Dose Equivalent Rate Meter
| Brand | SMACH |
|---|---|
| Origin | Fujian, China |
| Manufacturer Type | Authorized Distributor |
| Product Category | Domestic |
| Model | RN200 |
| Instrument Class | Neutron Dose Rate Meter |
| Form Factor | Portable |
| Radiation Type | Neutrons (n) |
| Detector Type | Pressurized He-3 Proportional Counter with Spherical Polyethylene Moderator |
| Measurement Range | 0.01 µSv/h – 99.99 mSv/h |
| Sensitivity | 2.83 cps/(nSv/h) referenced to ²⁵²Cf neutron source |
| Energy Response | 0.025 eV – 15 MeV |
| Angular Response Deviation | < ±10% over 4π geometry |
| Accuracy | ±10% (relative error) |
| IP Rating | IP65 |
| Operating Temperature | −15 °C to +50 °C |
| Battery Life | >30 h continuous operation |
| Communication Interface | USB |
| Alarm | Adjustable threshold with audible, visual, and vibration alerts |
| Cumulative Dose Range | 0.01 µSv – 9999 mSv |
| Moderator Dimensions | Ø210 mm × 320 mm, mass 5.5 kg |
| Moderator Material | Low-density polyethylene (ρ = 0.95 g/cm³) |
Overview
The SMACH RN200 Neutron Ambient Dose Equivalent Rate Meter is a portable, field-deployable radiation measurement instrument engineered for accurate and reliable assessment of neutron ambient dose equivalent rate, H*(10), in mixed-radiation environments. It operates on the principle of thermal neutron detection via a pressurized helium-3 (³He) proportional counter embedded within a spherically symmetric polyethylene moderator assembly. The moderator efficiently thermalizes incident fast and epithermal neutrons across an energy range spanning from thermal (0.025 eV) up to 15 MeV, enabling broad-spectrum response consistent with ICRP 74 and ISO 8529-1 reference conditions. Designed to meet operational requirements in nuclear facilities, regulatory inspections, emergency response, and industrial radiography, the RN200 delivers traceable, real-time neutron dose rate data compliant with international dosimetry conventions for radiation protection.
Key Features
- High-sensitivity ³He proportional counter operating at 8 atm pressure, coupled with a precisely engineered spherical low-density polyethylene (ρ = 0.95 g/cm³) moderator (Ø210 mm × 320 mm, 5.5 kg) for optimized 4π angular response
- Dual independent measurement channels: dedicated neutron and gamma detection pathways with separate alarm logic and real-time display
- Adjustable alarm thresholds with simultaneous audible, visual, and tactile (vibration) notification—configurable per IAEA Safety Guide RS-G-1.9 and national radiation protection regulations
- Robust mechanical architecture rated IP65 for dust and water resistance; operational across −15 °C to +50 °C, suitable for outdoor and harsh industrial deployment
- USB interface supporting bidirectional communication with host PC for firmware updates, parameter configuration, and raw data export in CSV or binary format
- Comprehensive dose reporting: instantaneous dose rate (0.01 µSv/h – 99.99 mSv/h), accumulated dose (0.01 µSv – 9999 mSv), and elapsed measurement time with timestamping
- Extended battery life (>30 h continuous use) with dual power options: rechargeable Li-ion pack or standard AA alkaline cells
Sample Compatibility & Compliance
The RN200 is validated for neutron field characterization in heterogeneous radiation environments, including moderated fission spectra (e.g., ²⁵²Cf), reactor leakage fields, accelerator-generated neutron beams, and cosmic-ray-induced albedo neutrons. Its energy response curve conforms to the ICRU Report 47 fluence-to-H*(10) conversion coefficients and satisfies the performance criteria outlined in ANSI N42.22-2022 for portable neutron survey instruments. The instrument meets electromagnetic compatibility (EMC) requirements per IEC 61000-6-2/6-3 and carries CE marking under the EU Radio Equipment Directive (RED) and Electromagnetic Compatibility Directive. While not certified to IEC 62327 for medical use, it supports GLP-aligned documentation workflows through audit-trail-enabled software logging and user-accessible calibration history storage.
Software & Data Management
The RN200 ships with SMACH Radiation Analysis Suite (SRAS), a Windows-based desktop application that enables full instrument control, spectral data visualization, and compliance-ready reporting. SRAS implements secure session management, user-level access control (operator/admin), and electronic signature support aligned with FDA 21 CFR Part 11 principles for regulated environments. All measurement sessions are timestamped and stored with metadata including GPS coordinates (if external module connected), detector temperature, battery voltage, and calibration factor ID. Export formats include ISO-compliant .rad files, CSV for third-party statistical analysis, and PDF reports with embedded instrument identification, calibration certificate references, and uncertainty statements. Firmware updates are delivered via signed package verification to ensure integrity and traceability.
Applications
- Routine monitoring and emergency response at nuclear power plants, research reactors, fuel fabrication facilities, and spent fuel handling areas
- Regulatory compliance surveys conducted by national radiation protection authorities, environmental agencies, and health physics departments
- Field deployments in oil well logging operations where pulsed neutron generators are employed for formation evaluation
- Border security, customs inspection, and nuclear forensics applications requiring rapid identification of illicit neutron-emitting materials
- Support of radiological emergency preparedness drills under IAEA Incident and Emergency Centre (IEC) protocols
- Academic and industrial neutron shielding validation studies using calibrated neutron sources and benchmark configurations
- Mobile environmental surveillance during decommissioning projects or post-accident remediation campaigns
FAQ
What neutron energy range does the RN200 cover, and how is energy compensation achieved?
The RN200 responds to neutrons from thermal (0.025 eV) to 15 MeV via moderation in its spherical polyethylene assembly. Energy compensation is realized through geometric optimization and ³He pressure tuning—not electronic correction—ensuring passive, stable response matching ICRP 74 H*(10) definitions.
Is the RN200 suitable for use in high gamma background environments?
Yes. Its dual-channel architecture includes a GM tube-based gamma channel with pulse discrimination logic, providing intrinsic gamma rejection exceeding 10⁴:1 for typical ¹³⁷Cs and ⁶⁰Co fields.
Can the RN200 be integrated into a fixed monitoring network?
While primarily designed as a portable unit, the RN200 supports optional mounting kits and external power adapters for semi-permanent installation. Data streaming via USB-to-Ethernet gateways enables integration into SCADA or centralized radiation monitoring platforms.
How often does the instrument require calibration, and what standards are used?
Annual calibration is recommended per ISO/IEC 17025-accredited laboratories using traceable ²⁵²Cf neutron sources and secondary standard rem meters. Calibration certificates include uncertainty budgets per GUM (JCGM 100:2008).
Does the RN200 provide dose equivalent rate in Sieverts or Rems?
The RN200 displays ambient dose equivalent rate H*(10) exclusively in SI units (µSv/h, mSv/h); no imperial unit (rem) output is supported to maintain alignment with IAEA Safety Standards Series No. GSR Part 3 and EURATOM directives.
