With too little time set, the central part of your load will not be sterilized regardless of the perfect readings on your gauge. If you set too much hold time, you'll waste energy and wear out the gasket, thus damaging heat-sensitive media. The main thing about the vertical autoclave timer setting directions is the following: it all depends on the hold time of your load, not the readi... https://www.bionicsscientific.com/blogs/web-stories/vertical-autoclave-timer-setting-guide/