The thermocouple has to be a minimum temperature. The oil filled tube site above the pilot light, and when it gets to hot, it shuts off the gas to the burners. Too cold, and it shuts off the gas to the pilot light (at least in the blodgett ovens I have rebuilt). A gas man I work with on them (he went through all the training on it) told me to use a propane torch on it INITIALLY, as the oil that is in the tube of the thermocouple, will gel and block the warm oil from getting back to the sensor part of the thermocouple. Once we got it to cherry red, and let it sit, the pilot stayed lit as the oil worked its way back.
The thermocouple controls the gas flow to the pilot and burners.
She couldn't tell the difference between the escape pod, and the bathroom. We had to go back for her.........................Twice.