MGP Instruments DMC 2000, DMC 3000 User Manual

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Users Guide for the Operational Dosimeter DMC

What is the purpose of an operational dosimeter?

The operational dosimeter (DMC) is an electronic dosimeter. It is worn in addition to the « passive »
personal dosimeter and allows you:

• to display your integrated dose in real time,

• to warn you with a beep of variable frequency of the radiation level around you

• to inform you when the alarm thresholds are exceeded :

o DMC2000 (cf. : Figure 1) : alarm and indicator light,
o DMC3000 (cf. : Figure 1) : alarm, indicator light and vibration,

• to register your operational dose to allow a daily Radiation Protection follow-up of your

interventions.

DMC 2000

DMC 3000

Figure 1: Photos of the two types of DMC used at CERN.

The alarm threshold for the dose rate is fixed at 2 mSv/h (corresponding to the dose rate limit in a Limited
Stay Controlled Radiation Area).
The dose alarm thresholds are fixed by the Radiation Protection Group according to the regulationary
annual limits and the dosimetric estimations registered in IMPACT activities.

If you hear an alarm, you must leave the area immediately and contact the Radiation Protection Service

on the site concerned:

- Meyrin : 72504

- Prévessin, SPS, LHC : 75252

Where do you have to wear an operational dosimeter?

Wearing a DMC is obligatory for all access to Limited Stay Controlled Radiation Areas and High-Radiation
Controlled Areas (cf.: Figure 2), from now on called Controlled Radiation Areas:

Figure 2: Controlled Radiation Areas where wearing a DMC is obligatory.

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How do you wear your operational dosimeter?

The DMC, just like the « passive » personal dosimeter(s) is worn at chest level.

How to use an operational dosimeter?

Until the month of March 2013:

At the entrance of Controlled Radiation Areas, you will find a form specifically for the registration of
received doses during the intervention (cf.: Figure 3). Every time you access the area, you must fill in a line
and complete every column. The DIMR number is replaced by the IMPACT number.

Figure 3: dosimetric registration sheets

New! From the month of March 2013 onwards:

A new automatic reading system for the DMCs has been put in place for the start of LS1 (cf.: Figure 4).

Figure 4: new system for automatically reading the operational dosimeters

The dose displayed by the DMC is expressed

in milli-sievert (mSv). In the example below,

one can read 0.468 mSv which is the

equivalent of 468 micro-sievert (µSv).