Heat Flow Meter – HFM 446 Lambda Series

The heat flow meter (HFM) is a fast, precise and easy-to-use instrument suitable for measuring the low thermal conductivity (λ) of insulation materials.

HFM 446 Lambda Series from NETZSCH is dedicated to both small and medium-sized specimens provided with excellent features.

SmartMode – Focused on Measurement, Evaluation and Reporting

The HFM software’s user interface fully supports the operator with a range of easily understandable features including reports, wizards, AutoCalibration and user methods.

Heat Flux Transducer – High Sensitivity and Accuracy

The dual heat flux transducers are used to monitor the heat flow to and from the sample. Signals that arise from the transducers are coupled electronically to account for many edge losses from the sample. For ΔT determination, three type K thermocouples on each transducer are distributed in the center, right and left side. They can be chosen and read in accordance with the European standards for HFM.

Determination of the Specific Heat Capacity

In addition to the thermal conductivity measurement, software and hardware allow for the measurement and determination of the specific heat capacity (cp).

Key Technical Data HFM 446 Lambda Series

Standards: ASTM C518, ASTM C1784, ISO 8301, JIS A1412, DIN EN 12667, EN 12664

Type: Stand-alone, with integrated printer

Air-tight system: Sample compartment with possibility to introduce purge gas

Motorized plate: Yes

Thermal conductivity range:

Up to 2.0 W/(m•K)2.0 W/(m•K) achievable with optional instrumentation kit, recommended for hard materials and those with higher thermal conductivity

Accuracy: ± 1% to 2%

Repeatability: 0.5%

Reproducibility: ± 0.5%All performance data is verified with NIST SRM 1450 D

Plate temperature range: -20 °C to 90 °C

Transducer metering: 102 mm x 102 mm

Chiller system: External; constant temperature setpoint over plate temperature range

Plate temperature control: Peltier system

Plate motion: Operator-actuated plate opening for fast sample change, quick return to setpoint

Plate thermocouples: Three thermocouples on each plate, type K (two extra thermocouples with instrumentation kit)

Thermocouple resolution: ± 0.01 °C

Number of setpoints: Up to 10

Specimen size:

HFM 446 Lambda Small: 203 mm x 203 mm

HFM 446 Lambda Medium: 305 mm x 305 mm

Specimen thickness (max.):

HFM 446 Lambda Small: 51 mm

HFM 446 Lambda Medium: 105 mm

Variable load/contact force:

HFM 446 Lambda Small: 0 to 854 N (21 kPa on 203 x 203 mm²)

HFM 446 Lambda Medium: 0 to 1930 N (21 kPa on 305 x 305 mm²)Precise load control and possibility to vary density of compressible materials; contact pressure calculated by software based on load sensor signal

Thickness determination:

Four-corner thickness determination via inclinometer

Compliance to non-parallel specimen surfaces

Software features:

SmartMode incl. AutoCalibration, report generation, data export, wizards, user methods, predefined instrument parameters, user-defined parameters, Cp determination, etc.

Storage and restoration of calibration and measurement files

Plot of plate/mean temperatures and thermal conductivity values

Monitoring of heat flux transducer signal