1.Introduvtion

   The film badge dosimeter or film badge is a personal dosimeter used for monitoring cumulative radiation dose due to ionizing radiation.

    The badge consists of two parts: photographic film, and a holder. The film emulsion is black and white photographic film with varying grain size to affect its sensitivity to incident radiation such as gamma rays, X-rays and beta particles.

    After use by the wearer, the film is removed, developed, and examined to measure exposure. When the film is irradiated, an image of the protective case is projected on the film. Lower energy photons are attenuated preferentially by differing absorber materials. This property is used in film dosimetry to identify the energy of radiation to which the dosimeter was exposed. Some film dosimeters have three emulsions, one for low-dose and the other for high-dose measurements. These two emulsions can be on separate film substrates or on either side of a single substrate. Knowing the energy allows for accurate measurement of radiation dose.

2. Personnel Monitoring In Iran

Personnel monitoring in the Islamic Republic of Iran is mainly carried out by the use of Film Badge which consists of a Fomma  Personnel Monitoring  flim carried in a RPRDS film Holder. The film holder is made of plastic material and has five different filters and an open window.

    Photographic film badge can be obtained from the Parsian Radiation Dosimetry Service (PRDS), that is approved by the National Radiation Protection Department (Iranian Regulatory Authority) to offer a personal monitoring service.

3.Instruction

    Film badge is issued to an individual who is occupationally exposed to radiation. It is for their use only and must not be used by any other individual or for any other purpose. 

  A photographic film must be used once only for the duration of its issue period.    At the end of that period it must be returned promptly to the PRDS for assessment of the radiation dose that it has recorded. A new photographic film badge dosemeter is issued for the next period of the monitoring period (2months).

Records of the dose received by each occupationally exposed person who is issued with a personal monitoring device must be kept by the employer as required by article 15 of the Radiation Protection Regulation 1369.

  Care must be taken with each personal monitoring device to ensure that it is not subjected to environmental conditions or mishandling which may affect its reading or damage the device. Factors that may cause adverse effects include mechanical impact and exposure to heat, chemicals or water.

4. Detection Limits

The minimum detectable photon doses by the film badge are:

• 0.12±0.04 mSv for photon high and
• 0.06±0.03 mSv for photon between 20 keV to 80 keV

5. Dose measuring range: 

• 0.01mSv to 1000mSv (photon  energy between 20 keV to 80 keV )
• 0.20mSv to 20000 mSv(photon  energy between 80 keV to 2 MeV)