Vielitzer Straße 43

95100 Selb

GERMANY

Tel.: 0049 9287 8800

Fax: 0049 9287 70488

Email: info@linseis.de

Linseis Inc.

20 Washington Road

P.O.Box 666

Princeton-Jct. NJ 08550Tel.: (609) 799-6282

Fax: (609) 799-7739

Email: info@linseis.com

The Company

Since 1957 Linseis Corporation delivers outstanding service, know how and leading innovative products in the field of thermal analysis and thermal physical properties. We are driven by innovation and customer satisfaction. Customer orientation, innovation, flexibility and last but not least highest quality are what Linseis stands for from the very beginning. Thanks to these fundamentals our company enjoys an exceptional reputation among the leading scientific and industrial companies.

Claus LinseisManaging Director

The Company

Linseis Germany

Vielitzerstr. 43

95100 Selb

Linseis USA

08550

Princeton Jct. / NJ

ASTM E 289

This test method covers the determination of linear thermal expansion of rigid solids using either a Michelson or Fizeau interferometer.

The precision of measurement of this absolute method (better than ±40 nm/(m·K)) is significantly higher than that of comparative methods such as push rod dilatometry (for example, Test Methods D 696 and E 228) and thermomechanical analysis (for example, Test Method E 831) techniques. It is applicable to materials having low and either positive or negative coefficients of expansion

Coefficient of Expansion

Definition of the Coefficient of Thermal Expansion

(CTE) The coefficient of thermal expansion is generally defined as the fractional increase in length per unit rise in temperature. The exact definition varies, depending on whether it is specified at a precise temperature (true coefficient of thermal expansion) or over a temperature range (mean coefficient of thermal expansion). The former is related to the slope of the tangent to the length – temperature plot, while the latter is governed by the slope of the chord between two points on this curve. Considerable variation in the value of the CTE can occur according to the definition employed.

L75 – LASER DILATOMETER

Features

• Michelson Principle Laser Dilatometer • Non contact expansion and shrinkage measurement • No calibration needed• Any solid sample material (reflecting & not reflecting)• Free choice of sample geometry • Sample preparation same as with conventional Dilatometer• Measurements under inert, oxid., red., vacuum• Maximum precision 0,3 Nanometer • temperature range -180 up to 1600°C (different furnaces)• Induction and heat resistance furnace possible

L75 – LASERThe System

Unmatched resolution and absolute accuracy is now possible due to the new development of the Linseis Laser Dilatometer of the Pico-series.

The system consists of three main components:

• The Michelson Interferometer

• The measuring system

• The furnace

The Michelson Interferometer

The used double plane-mirror interferometer is used for simultaneously making pairs of nanoprecision length measurements.

The He-Ne lasers, which is frequency stabilized on the used model, was specifically designed for making longer length measurements, along with corrections for environmental shifts in laser wavelength, thus providing the basis for the unbeaten metric precisions.

The Measuring System

Dilatometer of the Pico-series. As the name indicates already the resolution goes up to Picometers (0,3nm = 300 Picometer). That means resolutions can be obtained which are up to a factor 33,33 higher as the resolution that were possible up to date. On top the principle of interference measurement give the possibility for much higher accuracy’s, especially as some special computer calibrations are used. Up to now absolute accuracy’s of 1% were normal, with best accuracy’s up to 100nm. The new method allows accuracy’s up to 30nm.

L75 Laser 500LT

Laser Dilatometer with low temperature furnace

Temperature : -150 …500°C

Interferometer

Furnace

Gas Control

Interferometer

Electronics

L75 Laser

Laser Dilatometer with Induction Furnace

Temperature : -150 …1000°C

-150 …1600°C

Heat up and cool down speed 100K/s

Iron Sample

The Furnaces

Resistance Furnace

The system can be equipped with conventional resistance furnaces with a temperature range from:

• -150 …500°C• RT …1000°C

Induction Furnace

The system can be equipped with an induction furnaces with a temperature range from:

• -150 …1000°C• -150 …1600°C

Applications

Reproducibility of an INVAR Sample

An INVAR Sample was evaluated four times during heating in an air atmosphere. The temperature range was room temperature up to 200°C. The difference of the four measurements was as low as 0.01% FS.

Applications

Measurement of fused silica, NIST SRM739

*“Soll” represents the NIST value

Applications

Measurement of sapphire, cutting angle 0° to C-Axis

*“Soll” represents the literature value

Applications

Measurement of Copper, NIST SRM736

*“Soll” represents the NIST value

Applications

Measurement of polycrystalline Al2O3, Purity 99.7%

*“Soll” represents the literature value

Applications

• Precision measurement of thermal expansion of low expansion materials

such as: carbon, graphite, composites, low expansion glass, amber alloy,

quartz glass, etc.

• Precision measurement of thermal expansion of semiconductor materials.

• Quality control and quality inspection of materials of which thermal

expansion characteristics can be a problem, such as glass, sealing

materials, bimetals, materials for precision electronic instruments etc.