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There is common that read out from survey meter
using SI unit to express a dose rate, such as Sievert
based unit per hour. For the convineance, the relation-
ship between unit is crucial. Therefore, Table 6.2 pro-
vides the relationship of several unit used to describe
the radiation dose.

6.3 Gamma and Beta Dosimetry

URL : https://www.nde-ed.org/EducationResources/
CommunityCollege/RadiationSafety/radiation_safety_equipment/
pocket_dosimeter.htm (26/3/2020)

Direct Read Pocket Dosimeter

Direct read pocket dosimeter also known as pen dosime-
ter because it is designed about the size of a fountain
pen. It is used tiny ionization chamber as a radiation
detector with the volume approximately two milliliters.
This chamber has an anode wire at the central and
electrically connected with the metal coated quartz fiber.
The fiber has some flexibility depending on the charge
between the anode and fiber inside the ion chamber.Figure
6.3 shows the pen dosimeter and illustrate the inside
view consists of the device component.

Under the positive potential after recharging, the
electrostatic repulsion deflects the quartz fiber to start-
ing position. The net positive charge reduces when the

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