Got my digital thermometer from omega today and did a little test real quick with my curent heat treat setup. before it was just a guessing game as to how hot it was inside the brick , but now i know. it gets damn hot in there with mapp gas. i know now for a fact that i was WAY over heating my o1. with a new bottle from the time u turn valve on and get lightable gas its like 1 turn to get it to 1500 f, i was slightly shocked that it got so hot so fast. but good equipment like this meter helps u see the errors u can make buy guessing things like temp. Cant wait for this weekend when i can do a quality , accurate soak on some o1 blades i have profiled.