Seebeck Coefficient/
Electric Resistance
Measuring System
NEshWape sample
Disc A & LSR
e
m
a
S
for LF
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”.
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LSR-3 Seebeck
To enable advanced research in Thermoelectrics, LINSEIS offers a
Features
complete range of instruments for this demanding task. The instruments available involve Seebeck and Electric Resistivity - LSR, Thermal
The LSR - 3 can simultaneous measure both Seebeck coeffifi cient and
Diffusivity and Thermal Conductivity - LFA, Thermal Expansion and
electric resistance (Resistivity).
Density – Dilatometer, Specific Heat – DSC.
• Prism and cylindrical samples with a length between 6 to 22mm can
be analyzed
ZT=
S2 • s • T
l
S: Seebeck Coefficient; [S] = μV/K
I: Electrical Conductivity; [s] = 1/Ωm
K: Thermal Conductivity; [l] = W/mK
• 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
With the LSR measurement the Seebeck Coefficient
can be measured directly. The LSR device can also
determine the electric resistivity r. With the formula
s=
1
r
follows the electrical conductivity s.
reproducibility
• State of the art 32-Bit software enables automatic measurement
procedures
• Measurement Data can be easily exported
LSR-3 Seebeck
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Principles of Measurement
A sample of cylindrical or prism shape is vertically positioned between
accuracy measurements of the electromotive force dE at one wire of
two electrodes. The lower electrode block contains a heater, whilst
each of the two thermocouples.
the entire measuring arrangement is located in a furnace. The furnace
surrounding the measuring arrangement heats the sample to a
The dc four-terminal method is used to measure the Electric Resi-
specififi ed temperature. At this temperature the secondary heater
stance. By applying a constant current (I) at both ends of the sample
in the lower electrode block creates a set temperature gradient. Two
and measuring the change in voltage dV between one wires at each of
contacting thermocouples then measure the temperature gradient T1
the two thermocouple pares.
and T2. A unique thermocouple contact mechanism permits highest
3 Possible Sample Geometries
The LSR instrument can handle 3 different sample geometries, rod, bar
same sample in the LSR Seebeck & Electric Resistivity Analyzer and a
(square footprint) or disk shape.
LFA Laser Flash Analyzer.
The disk shape sample allows a direct measurement of one and the
LSR
LFA
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-100
90
-110
80
-120
70
-130
Resistivity ρ [µΩm]
100
Measurement of s: LSR
60
-140
50
-150
A4 Seebeck-Coefficient
40
-160
A4 Resistivity
30
-170
20
Seebeck-Coefficient s [µV/K]
Measurement of a sample of the tellur family
-180
Measurement of ρ: LSR
10
-190
0
-200
20
40
60
80
100
120
Temperature [°C]
140
160
180
200
Specifications
LSR 3
Temperature Range
-100 up to 500°C; RT up to 800/1100/1500°C
Measurement method
Seebeck coefficient: Static dc method
Electric resistance: four-terminal method
Specimen holder
sandwiched between two electrodes
Atmosphere
inert, oxid., red., vac.
Sample size
2 to 4 mm2 or diameter x 6 to 23 mm long
Sample size round (Disc shape)
10, 12.7, 25.4 mm
Lead interval
4, 6, 8 mm
Cooling water
required
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LINSEIS GmbH
Vielitzerstr. 43
95100 Selb
Germany
Tel.: (+49) 9287–880 - 0
Fax: (+49) 9287–70488
E-mail: info@linseis.de
LINSEIS Inc.
109 North Gold Drive
Robbinsville, NJ 08691
USA
Tel.: +01 (609) 223 2070
Fax: +01 (609) 223 2074
E-mail: info@linseis.com
Products: DIL, TG, STA, DSC, HDSC, DTA, TMA, MS/FTIR, In-Situ EGA, Laser Flash, Seebeck Effect
Services: Service Lab, Calibration Service
www.linseis.com