If you have a gas cooker in your kitchen, there's an important part that you ought to know about: the thermocouple.
The thermocouple isn't directly involved in cooking your food, but it's crucial to the safe running of your gas oven. This clever little part can tell if your appliance's pilot flame goes out; if this happens, the thermocouple will automatically shut off the gas flow to prevent the build-up of dangerous gas in your kitchen.
How does my oven thermocouple work?
The key part of the thermocouple is a probe that sits close to your oven's pilot flame. Another junction of the thermocouple rests in a cool part of your appliance where the temperature will remain consistently low no matter what.
When the pilot flame is burning, it heats the probe and causes a current to flow through the thermocouple's circuit. (This happens because one part of the thermocouple is hotter than the other - this is called the
thermoelectric effect.) That current is used to hold a small valve open, allowing gas to flow freely into the appliance.
If the pilot flame is extinguished for any reason, the probe cools, which interrupts the electrical current that was holding the valve open. As a result, the valve closes and prevents gas from flowing into the oven.
Why is this important?
If you didn't have a working thermocouple, gas would continue to flow into your oven even if the pilot light went out. This unburned gas would build up, and you would end up with dangerous levels of flammable gas in your home, greatly increasing the risk of a fire or explosion.
