Change of oxygen concentration according to argon purging of storage vault in ACPF

Fire and explosion may occur. These event also cause severe accident. Thus it is essential to measure the Oxygen concentration in the storage vault. Therefore, in order to measure the change of Oxygen concentration according to the amount of Argon in the storage vault, Oximeter was installed in the storage vault outlet to measure Oxygen concentration change. It uses 595.8L of Argon gas to reach 100ppm by purging Vault A and B at the same time. According to the MBRAUN data which is a famous company of making GLOVE BOX, it needs 11 times bigger volume of Argon gas to reach 100ppm. Also it needs 3,000L of Argon gas to purge to reach 100 ppm on this experimental volume which is 0.27m3. There is a big gap between the MBRAUN data and our experiment result. I guess there were on error on Assuming that everything is Argon gas except Oxygen gas which was measured only. It is hard to say that other substances is Argon gas (purity 99.999%) even the Oxygen is lower than 10 ppm.