游離腔有良好之穩定性，且信號易於量測，適台低於2MeV以下之光子輻射劑量量測。1992年，M Boutillon and A-M Pelloche應用圓餅形游離腔作爲Bureau International Des Poids Et Mesures (BIPM)量測水吸收劑量之標準；國家游離輻射標準實驗室參考其設計及技術，製作圓餅型游離腔，用以60Co水吸收劑量。依據量測原理經由實驗或引據正確資料以決定相關量測參數包括：游離腔內空氣質量、游離之電荷、乾燥空氣產生一離子對所需之能量、電子所帶之電量、電子能譜在石墨與空氣間之平均阻擋本領、光子能譜在水與石墨間之7平均質能轉移係數比值、光子能通量在水與石墨間之比值、水吸收劑量和克馬間之比值、光子能譜在水與石墨問之平均質能轉移係數、真實游離腔空腔對Bragg-Gray理想空腔的修正因子、游離腔收集電荷再結合修正因子，、游離腔支撐架修正因子、水假體射束入射表面非等水材質修正因子、射束徑向不均勻修正因子、空氣溼度因素修正因子。利用INER自製之游離腔和所獲得之量測參數，量測60Co水吸收劑量，以游離腔校正因子比對其結果和美國國家標準與研究院(NIST/USA)，差異爲0.17%；和澳大利亞輻射防護與核能安全機構(ARPANSA/Australia)的差異爲0.17%；和德國聯邦物理技術研究院(PTB/Germany)差異爲0.75%；可知量測60Co水吸收劑量和國際間其他國家標準量測具有一致性。應用ISO量測不確定度表示方式指引所述之方法進行不確度評估結果，組合不確度0.27%。

In Taiwan, the measurement of the output dose rates of medical accelerators is performed by using the ionization chamber that has been calibrated by the 60Co air kerma standard and the various conversion factors quoted from the AAPM TG21 protocol (1983), The AAPM published the TG-51 protocol in 1999 which recommended medical ionization chambers to be calibrated in water with the absorbed dose to water standard in 60Co. This protocol makes it more convenient to measure the absorbed dose rate to water of the accelerator. To meet the domestic demands of calibrating the ionization chamber in terms of the absorbed dose to water, the Institute of Nuclear Energy Research (INER) undertook the establishment of the primary standard of the absorbed dose to water in 60Co according to the requirements of the AAPM TG-51 in 2000, Since M Boutillon and A-M Perroche employed the pancake ionization chamber as the absorbed dose to water in 60Co standard of the Bureau International Des Poids Et Mesures (BIPM) in 1992, the design and measurement technology of the standard at INER was constructed referring to the BIPM. After the measurement and evaluation for the volume, parameters and correction factors of INER's pancake chamber, the obtained expanded uncertainty (k=2) of the absorbed dose to water in 60Qo was within 0.6%. At the same time, the comparison difference of INER's absorbed dose to water standard with those of ARPANSA, PTB and NIST was also within 0.8%. Thus, the Pancake chamber of INER has the capabilities to piovide the calibration traceability of the absorbed dose to water in Taiwan.