Knowledge Hub · Electronic Personal Dosimeter
Passive TLD / OSL badges are the legally-defined occupational dose record — but their monthly-cadence feedback loop is too slow to change operator behaviour. An electronic personal dosimeter reads in real time: the operator sees the dose-rate spike at the moment the exposure happens and adjusts. Badge + EPD together produce both the legal record and the behavioural feedback. This page walks why.
Why this matters
Passive vs active dosimetry
A passive TLD / OSL badge is the legally-defined dose record — sent to a national dosimetry service, read at monthly cadence, returned to the radiation-safety officer as a single accumulated-dose figure. An electronic personal dosimeter (EPD) is the real-time companion — it reads the current dose-rate and the within-shift accumulated dose on a screen the operator can see. The passive badge wins on legal record; the EPD wins on operator-behaviour feedback. The two together produce both records.
Based on: IAEA Safety Reports Series 16 — Calibration of Radiation Protection Monitoring Instruments; ICRP Publication 75.
Read source ↗Hp(10) — the operational quantity
ICRP Publication 74 defines Hp(10) — personal dose equivalent at 10 mm depth in tissue — as the operational quantity for whole-body external-exposure monitoring. The EPD reports directly in Hp(10), so the displayed value maps onto the AERB occupational-dose limit (20 mSv/year on a 5-year rolling average, 50 mSv in any single year) without any conversion factor that has to be defended at inspection.
Based on: ICRP Publication 74 — Conversion Coefficients for use in Radiological Protection.
Read source ↗Configurable alarms
Two independent alarm channels: one tracks accumulated dose over the day / shift / week; the other tracks instantaneous dose rate. The cumulative-dose alarm catches the operator who has accumulated more dose than expected by mid-day. The dose-rate alarm catches the operator who has walked into a stronger field than expected — typically before the cumulative dose has built up. Both run continuously; both trip in audible / visual / vibration mode operator-selectable.
Based on: IAEA Safety Reports Series 16; manufacturer product page.
Read source ↗Behavioural feedback loop
A month-end badge readout that surprises the operator with a higher-than-expected dose is informative but too slow — the exposure event happened weeks ago. A real-time EPD reading flags the dose-rate spike at the moment it happens; the operator steps back, adds shielding, asks for help. Operator behaviour changes within the shift. The cumulative monthly dose drops because the within-shift events change.
Based on: IAEA Safety Reports Series 40 — Operational Radiation Protection in Nuclear Medicine.
Read source ↗Theranostic workplace fit
Theranostic Lu-177 / I-131 nursing wards have high-activity patients and busy patient-care workflows. An audible alarm disrupts the patient. A vibration alarm at a configured dose-rate threshold gives the nurse a non-audible cue to step back — the patient stays comfortable, the nurse gets the feedback. The EPD's multi-mode alarm is built for the patient-care environment, not just the hot-lab dispensary.
Based on: EANM Safety Guidance for therapeutic nuclear-medicine wards.
Read source ↗AERB compliance
AERB Atomic Energy (Radiation Protection) Rules 2004 expect occupational-dose records for every radiation worker. The compliant dossier per worker is the passive-badge monthly record + the EPD shift log + the calibration certificate for each instrument. The EPD log feeds the dossier as continuous dose-rate history; the badge feeds the official cumulative dose. The combination wins at inspection.
Based on: AERB Atomic Energy (Radiation Protection) Rules 2004; AERB Safety Code for Nuclear Medicine Facility.
Read source ↗ICRP, IAEA and AERB documents that frame occupational personal dosimetry.
ICRP framework defining Hp(10) as the operational quantity for whole-body external exposure.
IAEA framework for personal dosimeter calibration including EPD vs passive-badge guidance.
IAEA framework for nuclear-medicine operational radiation protection including personal dosimetry expectations.
Indian regulatory framework for occupational radiation protection and personal dose records.
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