How to Prevent Vibration Damage to Thermocouples and RTD Sensors

Thermocouple in heater at an industry factory

All thermocouples utilize the Seebeck effect. This phenomenon occurs when a temperature difference between two metal conductors generates an electromagnetic force between them. The two metals are used together to measure changes in temperature. Because these pieces of equipment must operate at a particular temperature, thermocouples and resistance temperature detectors (RTDs) are essential, and if they are damaged, they will not function properly. Many times, these delicate pieces of equipment are damaged because of vibration. How do you prevent damage to thermocouples and RTDs?

How Do Thermocouples Protect Against Vibration?

Thermocouples are often covered with a protected metal sheath. That sheath helps to protect the thermocouple from vibration damage. If the thermocouple is housed within a metal sheath, there is much less chance of vibration.

However, there are times when the thermocouple is left unguarded or exposed in order to improve the time of response. Sometimes, this creates problems with vibration. There may also be an issue if the thermocouple is grounded close to machinery or other equipment, especially if there is a lot of noise.

Sensors often are wrapped in wire or a thin film. There are some sensors with a glass core, which are mainly used to measure liquids. If the sensor is wrapped in a thin film, it is better protected than a wire-wrapped sensor. It also gives them more sensitivity to changes in temperature.

How Do Thermocouples & Temperature Sensors Get Damaged by Vibration?

The main way that thermocouples and temperature sensors become damaged is usually due to vibration fatigue. When these pieces become damaged, the insulation fails and the thermocouple could short circuit.

You will know there is a damaged thermocouple when you begin to see abnormally high readings. The thermocouple could also become uncalibrated due to vibrations. If a thermocouple isn't calibrated, it isn't reading temperatures correctly.

If you have an RTD that is wired, they are susceptible to damage due to vibration. When RTDs are damaged, you may get an open circuit instead of a closed one as well as abnormally high temperature readings.

How Can Thermocouples & Temperature Sensors Be Protected Against Vibration Damage?

One way to protect thermocouples and temperature sensors against vibration damage is to purchase those that have extra protection against vibration damage. In many cases, these sensitive instruments are protected by an additional coil that helps to minimize vibrations.

You can also work to minimize vibration damage to thermocouples and temperature sensors by grounding them wherever possible. Often these pieces are damaged due to static electricity, and grounding them prevents this problem.

You can also choose to check thermocouples and temperature sensors regularly for vibration damage to make sure they are still properly calibrated. Constant reading of temperature will also help you determine if there is a problem with vibration in the machinery that is affecting your sensors or thermocouples.

RAM Sensors: Experts in Thermocouples & Temperature Sensors

By making sure that the thermocouples and temperature sensors are functioning correctly, you'll ensure your equipment or machinery is functioning at the right temperature. Contact us today for more expert advice on how to protect your thermocouples and RTDs from vibration damage.