Epd Displays, Alarms And Controls - Thermo Scientific DCS4 Manual

Issue: 1.78
Thermo Fisher Scientific

EPD Displays, Alarms and Controls

The Thermo Electronic Personal Dosemeters (EPD) are
described in detail in their own Technical Handbook (see EPD
Mk2 Technical Handbook Ref No. 611/HB/40521/000).
The EPD measures gamma, X-ray and beta radiation, and
calculates the combined equivalent accumulated doses and dose
rates for Superficial Dose (Hs) and Penetrating Dose (Hp),
measured in Sv. If the dose or dose rates exceed pre-set levels
(Alarm Thresholds), the EPD sounds and displays alarms.
Workers, using EPDs, register at an Access Control Terminal
(ACT) on entry to the Radiologically Controlled Area. They
register their personal identity and the task they have to do.
The ACT loads the EPD with the Alarm Thresholds appropriate
to the task. When they leave the area, they again present the
EPD to the ACT, which records the measured doses in the Dose
Control System database and clears the EPD's memory so that
it is ready to be used by another Worker.
Beta Receptor
The Beta Receptor (as indicated in the above drawings) is a
special film covering and must not be tampered with, and it
must not be covered by anything else when the EPD is in use.
The EPD has an LCD display which shows various information
to the wearer. In normal use, this shows the Hp dose measured
since entry to the RCA, with an alternating half-moon
"heartbeat" showing that it is working. If an alarm has been
triggered, it shows which threshold has been exceeded.
Mk2 EPD
A Guide to Using DCS4 Access Control Workstation
Introduction to DCS4
2-3