Bimetal disc thermostat functions well in high temperature environments

Thermostats, like the bimetal disc thermostat, are used in many devices to monitor fluctuating temperatures. One example is using a bimetal disc thermostat to monitor the temperature of an engine manifold. The goal here is to keep the temperature as close to an acceptable range as possible. The ability to withstand extreme temperature conditions is the key of the design of a bimetal disc thermostat.

Bimetal disc thermostats have come a long way

Years ago, thermostats built in cars used an inexpensive wax chamber. The chamber expanded as the temperature increased which pushed a plunger to activate a switch. Unfortunately, it had a tendency to drift and stop working completely over time. This made the device completely unreliable. Now there are more reliable products that work better and are much more reliable.

Bimetal disc thermostats come in a variety of choices. Each has its own advantages, so it's a good idea to research carefully before you buy. With bimetal disc thermostats, two different metals are used. Each metal piece has a different response to temperature changes. As soon as the temperature changes, each strip expands at a different rate. This causes the element to bend into the shape of an arc to make or break the set of contacts.

Thermostat issues you should be aware of

There is a drawback to using fused bimetal trips in bimetal disc thermometers. The switchover happens slowly - the closing from the metal expansion is not an immediate effect. Constant fluctuations in temperature would cause the contacts to continuously open and close. This exaggerates the arch and could potentially wear out the contact surfaces. This could cause a thermostat to prematurely malfunction.

The bimetal disc thermostat uses a snap acting bimetal disk. Unlike the fused bimetal disc thermostat, when the two metals of the snap acting bimetal disc thermostat join together and are heated, the metal that responds with low-expansion slows down the movement of the disk until high-expansion metal takes over. It then snaps down over the center. What this does is keep the disk away from the circuit to reduce the chance of wear and tear. What's more, if it is not preheated, then it will not drift over time, which makes a bimetal disc thermostat a durable and long lasting device.

Bimetal immersion thermostats

A bimetal disc thermostat can also withstand immersion in liquid substances. It can also be used to monitor the temperature within a liquid. A bimetal disc thermostat used to measure temperature in liquids was commonly used as part of engine protection. They were made of welded stainless steel. Now, a bimetal disc thermostat is designed as one piece is the most common way manufacturers create these types of thermostats. The one piece design is made of machine welded brass and a thick cross-section that is able to withstand extremely high temperatures.

Monitoring engine temperatures

Bimetal disc thermostats are used to alter an engine's operator once a certain engine temperature is reached. If the temperature drops below a certain temperature, the engine will only be able to idle until it warms to the right temperature - at least around 100 degrees Fahrenheit. The bimetal disc thermometer helps prevent damage to a cold engine.