Abstarct: The amount of energy left in a matter is called absorbent dose. The determination of absorbed dose is called radiation dosimeter. The absorption dose is measured according to the protocols defined by the International Atomic Energy Agency (IAEA). The standards defined by the IAEA are classified into two levels of primary and secondary standards. The primary standard includes tools that give the highest possible accuracy of a given quantity baxsed on its definition. The three main methods at the primary standard level are [1]: Free-air ionization chamber, calorimetry, and ferric dosimeter. The main focus of this project is on the free air ionization chamber. The secondary standard is defined according to the primary standard but is at a lower level in terms of accuracy. On the other hand, they are easier to use and cost less construction and maintenance. The Primary Standard Dosimetry Laboratory (PSDL) is responsible for providing primarily standards for radiation dosimetry and its working methods. In addition, the PSDL labs are also active in improving the basic standards and providing the required dosimetry data. On the other hand, the secondary standard dosimetry laboratory (SSDL), according to the standards and methodology defined by the PSDL, uses appropriate equipment to calibrate and provide services to other users of the beam. As stated above, secondary standards are calibrated baxsed on comparison with the primarily standards, so each SSDL center must be lixnked to a PSDL. In Iran, the standard laboratory of standard dosimetry is located in Karaj and it provides services to users according to the standards defined by the IAEA [1]. In order to periodically calibrate its equipment, the SSDL laboratory sends them to the International Atomic Energy Agency (IAEA) for a period of three years. Sending equipment to the IAEA requires a lot of time and money. There is also no possibility to send in shorter time periods. Accordingly, the design and development of a standard dosimetric laboratory were approved and implemented by the Atomic Energy Organization.