HFM 436 Lambda

Heat flow meter

Accurate thermal conductivity testing of insulation materials

With the Heat Flow Meter, HFM 436 Lambda, samples measuring 30.5 cm x 30.5 cm or 61 cm x 61 cm and of variable thicknesses ranging from a few millimeters to 10 (20) cm are tested between two heat flux sensors in fixed or adjustable temperature gradients. After a few minutes for the system to reach equilibrium, the built-in computer or external computer determines the thermal conductivity and thermal resistance of the sample.

Automatic plate movement and determination of the sample thickness facilitate test preparation.
The patented plate temperature control system (US-patent No. 5,940,784 (1999)) and dual heat flux sensors quickly provide accurate data.
All test parameters as well as the calibration data are stored in the computer and documented (only with separate software).

Enhanced Capabilities

  • Variable external load
  • Integrated printer
  • Extendable to higher conductivity materials with the optional instrumentation kit

Determination of thermal conductivity with the Heat Flow Meter, HFM 436 Lambda, meets the industry standards ASTM C518, ISO 8301, JIS A 1412, DIN EN 12939, DIN EN 13163, DIN EN 12667 and based on DIN EN 12664.


Key Technical Data

(subject to change)

Your device is too small to show this table.
HFM 436/3/0 HFM 436/3/1HFM 436/3/1E
Plate Temperature Ranges Fixed, 0°C to 40°C Variable, 0°C to 100°C  Variable, -30°C to 90°C
Cooling System AirAirExternal Chiller
Plate Temperature Control Peltier System   Peltier System   Peltier System  
Thermocouple Precision ± 0.01°C ± 0.01°C ± 0.01°C
Number of Programmable Temperatures 11010
Specimen Size
(L x W x H) mm
305 x 305 x 100305 x 305 x 100305 x 305 x 100
Thermal Resistance Range*0.1 to 8.0 m2⋅K/W;
with instrumentation kit down to 0.05 m2⋅K/W
0.1 to 8.0 m2⋅K/W;
with instrumentation kit down to 0.05 m2⋅K/W
0.1 to 8.0 m2⋅K/W;
with instrumentation kit down to 0.05 m2⋅K/W
Thermal Conductivity Range* 0.002 to 1 W/(m⋅K);
with instrumentation kit up to 2 W/(m⋅K)
0.002 to 1 W/(m⋅K);
with instrumentation kit up to 2 W/(m⋅K)
0.002 to 1 W/(m⋅K);
with instrumentation kit up to 2 W/(m⋅K)
Repeatability0.25 % 0.25 % 0.25 %
Accuracy± 1 to 3 % ± 1 to 3 % ± 1 to 3 %
(L x W x H) mm
480 x 630 x 510480 x 630 x 510480 x 630 x 510
Variable Load up to 21 kPa (Option)up to 21 kPa (Option)up to 21 kPa (Option)

Instrumentation kit

* Note 1: Samples should satisfy both ranges: Maximum thickness for lowest thermal conductivity will be lower than 25 mm, and minimum thickness for highest thermal conductivity is near 100 mm. When testing near the limits of these ranges, special techniques may be required for sample preparation, instrument calibration, and temperature measurement.
* Note 2: Instrumentation kit available for testing high conductivity (1 to 2 W/(m⋅K), low thermal resistance specimens <0.1 m²⋅K/W


All HFM 436 Lambda heat flow meters are controlled with the internal Q-Test software, embedded on a microprocessor. Tests are programmed from the keypad and the results can be printed directly from the instrument.
Programming, evaluation and data storage for calibration and sample measurements can be managed with even more flexibility via an external computer and the Q-Lab software (32-bit Windows® operating system).


  • Instrumentation Kit for Materials with Higher Thermal Conductivity
    The HFM 436 Lambda can be equipped with an optional instrumentation kit that extends its range to higher thermal conductivity materials like concrete, wood products, brick. These materials are normally beyond the capability of the HFM, and often rigid, which can lead to a high, significant thermal contact resistance and non-uniform heat flow. The optional kit includes thin, compressible pads for use at both interfaces, and auxiliary thermocouples to be placed on the surfaces of the specimen to ensure best thermal contact and temperature control.

  • Variable External Load
    This feature, unique to the HFM 436 Lambda, allows the operator to apply a precise load on the specimen, enabling control of the thickness, and thus density, of compressible materials. It also ensures that the plates make intimate contact with the specimen across the entire surface to produce a minimal thermal contact resistance and an uniform heat flow, two necessary requirements for obtaining reproducible thermal conductivity results.

  • Standard samples for calibration




Product brochure: Thermal Conductivity; Methods, Technique, Applications, 16 pages


Application brochure: "Material Characterization, Phase Changes, Thermal Conductivity", 24 pages



Our poster “Thermal Properties of the Elements” shows the following values at a glance: melting point, boiling point, specific heat, heat of fusion, thermal expansion coefficient, thermal conductivity and density.


Digital Media


NETZSCH Webinar HFM Uglass
NETZSCH Webinar Heat Flow Meter Technique
NETZSCH-WebinarStandards-compliant Quality Assurance on Insulating Materials
NETZSCH-WebinarCommonly Used Method for Thermal Conductivity Determination

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