Take out the inner barrel of the pressure steam sterilizer, and then add an appropriate amount of water into the outer pot. When the water surface is equal to the triangular shelf, it will be fine. I don’t know if you have noticed this when filling water. It should be noted that neither the mouth end of the Erlenmeyer flask nor the test tube should be in contact with the wall of the barrel. This is because we do not want the condensed water to wet the wrapping paper and penetrate into the tampon.

Another point is adding a cover, which is a common operation when we operate the pressure steam sterilizer, but we often make mistakes during the operation. We must insert the exhaust hose on the cover into the exhaust groove of the inner barrel Inside. Then tighten the two opposite bolts at the same time in a symmetrical manner in pairs, and it must not cause air leakage.

After the required time is completed, be sure to cut off the power or turn off the gas to let the temperature inside the pressure steam sterilizer drop naturally. At this time, when the pressure on the pressure gauge drops to 0, open the exhaust valve, loosen the bolts, and open the cover carefully. Take out the item. Of course, if you find that the pressure gauge has not dropped to 0, we must not open the exhaust valve, because as long as the exhaust valve is opened, the pressure in the pot will suddenly drop, and the culture medium in the container will be rushed out due to the imbalance of internal and external pressure. The mouth of the flask will cause contamination of the tampon with the culture medium, and our operation will end in failure.