Thermo Scientific EPD-G Electronic Personal Gamma Dosimeter

Overview

The Thermo Scientific EPD-G Electronic Personal Gamma Dosimeter is a compact, rugged, and highly reliable portable instrument engineered for real-time measurement and recording of personal dose equivalent Hp(10) from X-ray and gamma (γ) radiation fields. Based on the proven architecture of the EPD MK2 platform, the EPD-G retains full mechanical and ergonomic compatibility while optimizing performance specifically for photon-dominated environments—where beta radiation monitoring is not required. It operates on the principle of solid-state charge collection in a multi-stage detector assembly, enabling stable, low-drift response across an exceptionally wide energy range (15 keV to 10 MeV) and dose span (1/64 µSv to 16 Sv). Its design adheres to international standards for personal dosimetry, including IEC 61526:2010, ensuring traceable, auditable, and metrologically sound measurements suitable for regulatory reporting and long-term occupational health surveillance.

Key Features

• Multi-stage solid-state detector optimized for photon response, delivering high linearity and minimal angular dependence across broad energy spectra.
• Configurable alarm thresholds for both cumulative dose and instantaneous dose rate, with adjustable audio volume and visual indicators compliant with EN 61000-6-3 EMC requirements.
• Dual power options: standard AA alkaline batteries (8-week operational life) or extended-life 3.6 V lithium battery (5-month operational life), both supporting hot-swap capability without data loss.
• Non-volatile memory with 10-year data retention without power; stores time-stamped peak dose rate events, cumulative dose history, and user-defined logging intervals as low as 1 second.
• Password-protected memory partition ensures data integrity and prevents unauthorized modification—critical for GLP/GMP-aligned dose recordkeeping and audit readiness.
• Unit flexibility: displays dose and dose rate in Sv, rem, Gy, or rad with appropriate SI prefixes (µ, m, k), configurable per user preference or regional regulatory requirement.

Sample Compatibility & Compliance

The EPD-G is intended exclusively for monitoring external exposure to penetrating X- and γ-radiation in occupational settings—including nuclear medicine departments, industrial radiography, research reactors, decommissioning sites, and emergency response operations. It is not designed for neutron, alpha, or beta particle detection. The device complies with IEC 61526:2010 for personal dosimeters measuring Hp(10), and its energy response curve satisfies the reference conditions defined in ISO 4037-1 for calibration using standard X-ray and gamma sources (e.g., ¹³⁷Cs, ⁶⁰Co, ²⁴¹Am). It supports traceable calibration against national standards laboratories and is compatible with Thermo’s ADS (Automated Dose System) software suite for centralized dose management, batch reporting, and integration into enterprise-level radiation safety programs.

Software & Data Management

Data retrieval and configuration are performed via USB interface using Thermo’s ADS software, which provides full readout, analysis, and archival functionality. ADS supports automated import of dose logs, generation of individual and group dose reports aligned with ICRP and national regulatory formats (e.g., NRC Form 5, UK HSE RIDDOR), and export to CSV, PDF, or XML for integration with LIMS or EHS platforms. Audit trail features include user login tracking, timestamped parameter changes, and immutable dose record signatures—meeting FDA 21 CFR Part 11 requirements for electronic records when deployed in regulated pharmaceutical or medical device manufacturing environments.

Applications

• Routine personal dosimetry for radiographers, nuclear technicians, and reactor operators working in controlled areas.
• Temporary deployment during maintenance, refueling, or decommissioning activities where rapid dose assessment and historical trending are essential.
• Emergency response dosimetry for first responders entering potentially contaminated zones, where immediate feedback and post-event reconstruction of exposure profiles are critical.
• Validation and verification of shielding effectiveness and work planning in radiotherapy facilities and industrial irradiation plants.
• Supporting ALARA (As Low As Reasonably Achievable) program implementation through granular, time-resolved exposure analytics.

FAQ

Does the EPD-G measure beta radiation?
No. The EPD-G is optimized exclusively for X- and γ-radiation detection. It does not provide reliable response to beta particles due to its detector housing design and energy threshold configuration.
What is the minimum detectable dose equivalent?
The instrument achieves a practical lower limit of detection (LLD) of approximately 1/64 µSv (15.6 nSv) under typical background conditions, consistent with IEC 61526 sensitivity requirements.
Can dose data be exported for regulatory submission?
Yes. ADS software generates compliant reports in multiple formats—including NRC-mandated templates—and supports digital signature, version control, and audit log export for regulatory audits.
Is calibration traceable to national standards?
Yes. Thermo Scientific offers factory calibration traceable to NIST (USA) or PTB (Germany), and field recalibration services are available through authorized service centers accredited to ISO/IEC 17025.
How is data security maintained during transfer?
All communication between the EPD-G and ADS software uses encrypted USB protocols; stored dose records are write-protected and require password authentication before modification or deletion.