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Seebeck Coefficient/
Electric Resistance
Measuring System
NEWSame Disc shape sample
for LFA & LSR
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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 combusti-
on 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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To enable advanced research in Thermoelectrics, LINSEIS offers a
complete range of instruments for this demanding task. The instru-
ments available involve Seebeck and Electric Resistivity - LSR, Thermal
Diffusivity and Thermal Conductivity - LFA, Thermal Expansion and
Density – Dilatometer, Specific Heat – DSC.
ZT=
S: Seebeck Coefficient; [S] = μV/KI: Electrical Conductivity; [s] = 1/ΩmK: Thermal Conductivity; [l] = W/mK
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= follows the electrical conductivity s.
Features
The LSR - 3 can simultaneous measure both Seebeck coeffifi cient 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
LSR-3 Seebeck
LSR-3 Seebeck
S2 • s • T l
1 r
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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 Resi-
stance. 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.
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
specififi ed 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
3 Possible Sample Geometries
The LSR instrument can handle 3 different sample geometries, rod, bar
(square footprint) or disk shape.
The disk shape sample allows a direct measurement of one and the
same sample in the LSR Seebeck & Electric Resistivity Analyzer and a
LFA Laser Flash Analyzer.
LFA
LSR
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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
Specifications
Resi
stiv
ity ρ
[µΩ
m]
100
90
80
70
60
50
40
30
20
10
0
Temperature [°C]20 40 60 80 100 120 140 160 180 200
Seeb
eck-
Coef
ficie
nt s
[µV/
K]
-100
-110
-120
-130
-140
-150
-160
-170
-180
-190
-200
Measurement of s: LSR
Measurement of ρ: LSR
A4 Seebeck-Coefficient
A4 Resistivity
Measurement of a sample of the tellur family
LINSEIS GmbHVielitzerstr. 43
95100 SelbGermany
Tel.: (+49) 9287–880 - 0Fax: (+49) 9287–70488E-mail: [email protected]
LINSEIS Inc.109 North Gold DriveRobbinsville, NJ 08691USATel.: +01 (609) 223 2070Fax: +01 (609) 223 2074E-mail: [email protected]
www.linseis.com
Products: DIL, TG, STA, DSC, HDSC, DTA, TMA, MS/FTIR, In-Situ EGA, Laser Flash, Seebeck Effect Services: Service Lab, Calibration Service
