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Thermal Properties Analyzer

Thermal Conductivity (Lambda), Ash Fusion, Thermal Screening, Microscopic Hot/Cold Stage, Wafer Chuck, Thermal Plate, Thermal Probe Station

나노유체 열전도도측정기 - LAMBDA Thermal Conductivity Meter

LAMBDA는 ASTM D7896-19에 따른 열선법을 사용하여 넓은 온도와 압력 범위에서 열전도도와 열확산율, 비열을 신속하게 측정 하는 사용자 친화적 Transient Hot Wire (THW) method의  열전도도측정기입니다. 본 제품의 우수성은 유체의 대류현상 없이, 정확하고 재현있는 열전도도 측정하는 데 있으며, 실험실과 현장에서 nanoparticle dispersion 및 나노유체, 열유체, 절연유의 정확한 열전도도의  측정이 가능합니다.

 


LAMBDA 열전도도측정기는 독립형 모드 (stand-alone mode) 또는 RS-232/USB를 통해 Windows 컴퓨터에서 직관적인 소프트웨어로 기기 구동과 열전도도를 측정합니다.

Key features

  • highly accurate laboratory instrument
  • wide measuring range (10 - 2000 mW/mK)
  • thermal conductivity and temperature are displayed
  • fast, instationary resistance measurement by means of the hot wire method
  • conforms to ASTM D7896-19
  • robust stainless steel sensor
  • wide temperature range (-50°C to 300°C)
  • no unwanted influence of convection
  • suitable for any fluid, powder or gel
  • requires only small sample volumes (approx. 40 ml)
  • high repeatability (± 1%)
  • short set-up time
  • quick and easy to operate
  • RS-232/USB connection to your PC for automatic measurement and temperature control
  • functional LAMBDA software included
  • optional thermostat available for automatic sample temperature control

 

Easy and fast measurement

LAMBDA를 사용한 열전도도를 측정 시 40ml의 소량 샘플이면 충분합니다. Hot wire 열선이 있는 센서를 샘플에 담그면 LAMBDA는 1분 간격으로 유체의 온도와 열전도도를 측정합니다.

 

Fields of application

컴팩트하고 매우 정확한 본 기기는 실험실과 현장 모두에서 유연하게 적용하는 새로운 가능성을 열어줍니다:

  • Optimization of fluid development: HTF, 실리콘 오일, 절연유 등의 개발을 개선할 수 있습니다.
  • Optimization of fluid applications: 열 물성 관련 문제를 해결하거나 공정 중에 열 전달 특성을 최적화할 수 있습니다.
  • Quality control: 입고되거나 출하하는 유체의 열전도도를 확인할 수 있습니다.
  • Fluid analysis in the field: 서비스 및 유지 보수 기간을 최적화할 수 있습니다.

 

Modes of operation

Thanks to its intuitive menu the LAMBDA meter can be operated in stand-alone mode. In addition you may use your PC with our powerful LAMBDA software to set up automatic conductivity measurements within a temperature range of your choice. The captured CSV-based data can be exported easily, e.g. to EXCEL, for your further analysis.

 

 

Optional thermostat for automatic sample temperature control

열전도도측정기 모델 LAMBDA에 의해 자동으로 제어될 수 있는 다양한 적합한 온도 조절 장치((thermostats)를 제공하므로 필요한 모든 샘플 온도를 신속하게 설정할 수 있어, 온도에 따른 열전도도측정이 가능합니다.

  • Dry-block thermostat (standard, as shown below): RT to 300°C
  • Julabo fluid thermostat with heat exchanger vessel for additional cooling: -25°C (or below) to 300°C

 

Technical data

Suitable media
fluids, gels, powders
Sample quantity
approx. 40 ml
Test standard
conforms to ASTM D7896-19
based on ASTM D2717
Measuring range
10 to 2,000 mW/(m*K)
Repeatability limit
1 %
Temperature range - sensor
-50°C to 300°C
Temperature accuracy
± 0.1 K
Temperature measurement
PT100
Pressure range - sensor
0 to 35 bar (optional HP version up to 500 bar available)
Measuring time
approx. 60 s
Connectivity
RS-232 interface (adaptable to USB)
Display
LCD (4 x 16 digits)
Dimensions electronic unit (LxWxH)
370 x 235 x 150 mm
Weight - system
approx. 2.9 kg
Power supply
110 - 240 V AC, 50/60Hz
Energy consumption
15W
Outer dimensions sample vessel (screw-on cup)
D = 38 mm (equals inner diameter of thermostat jacket);
L = 110 mm (equals immersion depth into thermostat)
Optional accessories
Dry-block thermostat for automatic testing above RT
Fluid circulator w/ extra vessel for testing below RT

 

The Thermal conductivity system LAMBDA
나노유체 열전도도측정기 - LAMBDA Thermal Conductivity Meter

LAMBDA is a compact, operator-friendly transient hot wire instrument that facilitates a fast determination of the thermal conductivity in a wide temperature and pressure range by means of the hot wire method according to ASTM D7896-19. This highly accurate athermal calorimeter is suited for fluid analysis in the laboratory as well as in the field, including the measurement of thermal conductivity of nanoparticle dispersions/nano fluids. The LAMBDA thermal conductivity meter can be operated either in stand-alone mode or with the intuitive software (incl.) on your WINDOWS computer via RS-232/USB.

Easy and fast measurement
For determining the thermal conductivity with LAMBDA a small sample volume of 40 ml is sufficient. Simply immerse its sensor with the hot wire into the sample and LAMBDA will determine the thermal conductivity as well as the temperature of your fluid in a one minute interval.
 

What is Thermal conductivity


The thermal conductivity lambda (λ) of a solid, a fluid or a gas may basically be understood as the speed at which a defined amount of heat travels as it goes through a particular substance. A low λ value means low thermal conductivity.

For both liquids and gases lambda highly depends on the temperature, whereas pressure dependence is comparitively low. The measure for lambda is W/(m*K) (Watts per Meter and Kelvin).

Typical lambda values for different fluids

Fluid Thermal conductivity λ (W/(m*K))
gasoline 0,140
glycerin 0,286
machine oil 0,126
ethanol 0,185
water @ 50°F (10°C) 0,580
water @ 140°F (60°C) 0,644

 

Lambda measurement for fluids, pastes and gels (flucon LAMBDA)

flucon's Measuring system LAMBDA allows you to determine the temperature-dependent thermal conductivity of liquids, pastes or gels with ease. With its hot-wire technology the LAMBDA is both precise and comfortable to handle. Its measuring range from 0,01 to 2 W/(m*K) and its temperature range -50°C to 150°C (HT version for even higher temperatures available) make it the perfect tool for your thermal fluid analysis.

 

Workflow for the determination of the thermal conductivity (flucon fluid analysis)

flucon not only offers their portable LAMBDA measuring system but also in-house fluid analysis in our own high pressure laboratory. Customers may send in small samples (300 ml) of the fluid they would like to have tested and then the following steps will be performed:

  • Laboratory measurement of the thermal conductivity as a function of temperature and pressure using a transient measuring method preventing an influence of convective flow of heat on the measuring result
  • Mathematical description of the pressure/temperature-dependant thermal conductivity
  • Graphical data preparation

 


Fundamentals of measuring λ


Stationary vs. instationary method

There are two ways of measuring thermal conductivity: the stationary and the instationary method. The stationary method is principally simpler as it proceeds from a constant temperature level, whereas the instationary method takes the problem of a changing temperature field into account. There is an advantage resulting from this extra effort however: the instationary method provides measuring results for the thermal conductivity much faster and the results are less influenced by convection.

The effects of convection for the stationary method

According to POLTZ the stationary method is seriously hampered by the fact of thermal conductivity induced by convection. In Tuluol, for example, an average flow rate of only o.01 mm/min leads to a deviance of about 1% in the data obtained for the thermal conductivity due to free convection. Therefore, POLTZ concludes that the stationary method, especially in an experimental set-up where the thick layers are concerned, cannot provide measuring data without a noticeable influence of convection. Furthermore, great care must be taken to avoid any kind of forced convection, such as would be caused by vibration of the measuring apparatus.

Measuring lambda. With LAMBDA.

The LAMBDA Thermal Conductivity Meter developed by flucon will give you the advantages of the fast instationary transient hot-wire method while at the same time excluding the influence of convection in the measuring process. This is achieved by computational processing of the data obtained within very short periods of time (approx. 800 ms) which in turn leads to a very short over-all duration of the test process (approx. 60 s).

The hot-wire of the LAMBDA serves as the source of heat and as the transducer at the same time. In order to raise the temperature, the hot-wire is subjected to a constant measuring current; as the surrounding medium warms up, the resistance of the hot-wire will change in accordance with the thermal viscosity of the surrounding medium. Thus the change of voltage in the hot-wire indicates the change of temperature taking place in the surrounding medium.


 

 

flucon fluid control GmbH, Germany
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