The Thermal power, thermoelectric power, or Seebeck coefficient of a material measures the magnitude of an induced thermoelectric voltage in response to a temperature difference across that material. The thermal power has units of (V/K).
In recent years much interest has been shown in various methods of direct conversion of heat into electricity. Waste heat from hot engines and combustion systems could save billions of dollars if it could be captured and converted into electricity via thermoelectric devices
For this challenging application Linseis has developed a characteristic evaluating instrument for these materials and devices; the LSR-3 “Linseis - Seebeck & Electric Resistivity Unit”.
The LSR - 3 can simultaneous measure both Seebeck coefficient and electric resistance (Resistivity).
- Prism and cylindrical samples with a length between 6 to 22mm can be analyzed
- Wires and Foils can be analyzed with a unique measurement adapter
- Three different exchangeable furnaces cover the temperature range from -100 up to 1100°C
- The design of the sample holder guarantees highest measurement reproducibility
- State of the art 32-Bit software enables automatic measurement procedures
- Measurement Data can be easily exported
Principles of Measurement
A sample of cylindrical or prism shape is vertically positioned between two electrodes. The lower electrode block contains a heater, whilst the entire measuring arrangement is located in a furnace.
The furnace surrounding the measuring arrangement heats the sample to a specified temperature. At this temperature the secondary heater in the lower electrode block creates a set temperature gradient. Two contacting thermocouples then measure the temperature gradient T1 and T2. A unique thermocouple contact mechanism permits highest accuracy measurements of the electromotive force dE at one wire of each of the two thermocouples.
The dc four-terminal method is used to measure the Electric Resistance. By applying a constant current (I) at both ends of the sample and measuring the change in voltage dV between one wires at each of the two thermocouple pares.