测量流体的导热系数一般用到稳态法和瞬态法，但是由于有对流的影响，瞬态法具有很多优点：
瞬态法考虑了变化的温度场的问题，测量时间快得多，结果受对流影响较小。仅0.01mm/min的平均流速会导致由于自由对流而引起的1%的偏差。因此，稳态方法，特别是在涉及厚层的实验装置中，不能提供不受对流影响的测量数据。此外，还必须非常小心地避免任何种类的强制对流，例如由于测量装置的振动引起的。
LAMBDA系统是一个紧凑的，界面友好的仪器，通过根据ASTM 热线法，可以在一个非常宽的温度和压力范围内测定导热系数，适用于实验室和现场的流体分析连接操作，包括纳米颗粒分散流体的热导率测量，LAMBDA可以独立操作或者和计算机，配备RS232接口。
- 显示导热系数和温度
- 通过热线法快速稳定地进行电阻测量
- 没有对流的影响
- 适用于任何流体、粉末和凝胶
- 只需要少量样品（35ml）
- 高重现性99%
- 设置时间短
- 易于操作
- 可选连接到计算机，用于全自动测量和温度控制。
Electronic unit LAMBDA
Instationary heat wire resistance measurement in accordance with ASTM D7896
Thermal conductivity 10 to 2.000 mW/mK
Accuracy +/- 2 % reading
Reproducibility +/- 1 % reading
Repeatability +/- 0.5 % reading
Temperature sensor PT100 +/- 0.1o C
Specific heat (computed) 0.1 to 1 cal/g o C
Measuring time approx. 30 s
Display: LC-Display
Digital interface: RS 232
Analog interface: 0…10 V or 4…20 mA
(thermal conductivity)
0…10 V or 4…20 mA
(temperature)
controller interface: RS232 ( heating unit)
Housing: Design electronic housing
Size/weight (approx.): 230*350*140 mm, 3 kg
Power supply: 110-230 VAC, 50/60 Hz
Ambient temperature: 10 to 40o C
Sensor unit LAMBDA
Heat wire element: Pt
Dimensions: designed to be screwed
into measuring chamber
(see 4.3)
Material: stainless steel
Temperature sensor PT100 +/- 0.1°C
(integrated)
Sensor cable: L = 1 m
Temperature range: -50°C to 300oC
Measured medium: fluids, powders, gels &
pastes
Measuring chamber LAMBDA
Stainless steel chamber
Containment: D=36 mm, L=90 mm
Material: stainless steel
Temperature range: -50°C to 300°C
Pressure range: 0 to 35 bar
Interface cable RS232 (LAMBDA – PC)
Software LAMBDA System
(operating system WINDOWS XP and
higher versions)
恒温配置：
Block thermostat for EPSILON+ / LAMBDA
for the fully automatic determination of the dielectric
properties of fluids as a function of temperature
Type CL-355A-230
Temperature range Room temperature to 400
degree C (by use with the
EPSILON+ up to 180° C
& up to 300°C with the
LAMBDA) Temp. stability +/- 0,3 degree C
Temp. set manually & automatically
Power supply 230 VAC, 50/60 Hz
Controller interface RS232
