HI Bettyboop, It also depends which tourniquet machine you are using. Some tourniquets pause the time when you deflate and then resume it when you inflate the tourniquet again. Therefore the tourniquet displayed would be the correct tourniquet time. Most ATS sytems by Zimmer and the PTS sytems by Delfi all do this. They also count up while others count down... If you really want to know go back to the manufacturer specs and double check.