Generally, when measuring thermal conductivity there’s not one method that fits every requirement. C-Therm have acknowledged this by making a Trident system that encompasses three different transient sensors. Their Trident system is a modular system in which you can have any combination of the sensors, from their modified transient plane source (MTPS) to the flex transient plane source (TPS) or their transient line source (TLS). These sensors can be used in thermal chambers as well as glove boxes.
Modified Transient Plane Source (MTPS)
The MTPS is the easiest method that C-Therm has developed to measure thermal conductivity and effusivity, it also complies to ASTM D7984. The single sided “plug and play” system has a patented heated guard ring and sensor coil to apply a small amount of heat throughout the sample, this induces a voltage drop in the sensor and this can be used to determine thermal properties of your sample in a matter of seconds.
This sensor is calibrated from the factory and there is a choice between settings on the software. The MTPS can be used for most applications such as: batteries, composites, nanomaterials, insulation and phase change materials. Whilst testing, the MTPS can measure up to 500 W/mK and both the sensor and cable are rated for temperatures up to 200 °C.
Transient Plane Source (TPS)
The TPS is a flexible double-sided sensor that comes in a range of sensor sizes for different sizes of sample. This sensor conforms to ISO 22007-2 and GB/T 32064 and records thermal conductivity, thermal diffusivity and specific heat capacity. The TPS requires two identical samples for the double-sided flexible sensor. The thickness of the sample being the diameter of the chosen sensor at a minimum. After a scouting run with this sensor, the power and time required for the test can be estimated and the parameters can be altered. Results can be qualified by checking ISO 22007-2.2. The TPS can be used for a large variety of applications such as: metal sheets, polymers, porous ceramics and building materials; the sensor can also have different utilities, used for testing thin films and anisotropic samples.
Transient Line Source (TLS)
The TLS is a probe method used for testing the thermal conductivity of samples such as viscous liquids such as polymer melts as well as granular materials. This probe is not ideal for less viscous liquids due to the effects of convection and how this affects the thermal conductivity value. This method adheres to the ASTM standards, D5334 and D5930. The electrically heated probe is placed into the sample with the rate of increase in temperature along the probe as a function of logarithmic time being used to calculate thermal conductivity.
For more information on these sensors, contact us or visit the C-Therm website.
Contact us if you’d like to book a demo, find out more information or organise sample testing with the C-Therm Trident system.