Thermtest Instruments Heat Flow Meter (HFM-100 HT/HFM-100/HFM-50) Model：HFM-100 HT/HFM-100/HFM-50

The Heat Flow Meter is an easy-to-use technique for measuring the thermal resistance and thermal conductivity of insulation products, construction materials, packaging and assemblies. Thermal conductivity is the measurement of the ability of a material to conduct heat and can be critical for defining energy efficiency and thermal performance in materials. Our HFM series was designed and engineered to combine the highest accuracy, repeatability, widest temperature range and industry leading performance all at an exceptional value.

 

The second generation HFM-100 / HFM-100 HT / HFM-50 instruments are an excellent choice when making steady-state thermal conductivity measurements of specimens like insulation products and construction materials. We’ve rigorously engineered the Heat Flow Meter (HFM) to meet the requirements of international standards including ASTM C518, ASTM C1784, ISO 8301, JIS A1412, EN 12667 and EN 12664. Operating the HFM is straightforward—a sample is positioned between two heating and cooling plates. The upper plate, powered by stepper motors positioned in each corner, lowers to contact the top of the sample. Plate contact with the test specimen is controlled by a standard applied pressure, or by a user defined specimen thickness.
Stepper motors are controlled by individual optical encoders for the measurement of sample thickness (L), to the nearest 0.05 mm (0.0019 in). Integrated logic between stepper motors allows the upper plate to sense and adjust for specimens with surface variations, optimizing plate – specimen contact for measurements. One heat flux sensor is integrated into each plate, and is used to monitor heat flux (Q/A), generated due to the difference in temperature (ΔT) between the top and bottom plate at regular intervals, until steady-state heat flux is observed. The composite heat flux is then used to measure thermal resistance (R) and calculate thermal conductivity (λ) according to Fourier’s Law.

Following international standards, the HFM-100 is designed for testing both homogeneous and heterogeneous materials. The HFM-100 / HFM-50 sample size allows for representative testing of materials typically found in insulation and construction industries.
 

Materials	Insulation, Solids, and Textiles
Type of Sensors	Flux Sensors (x2)
Surface Thermocouples	Three for each flux sensor
Applications	General Testing
Direction	Through-Thickness
Factory Calibrated	Yes
Thermal Conductivity Range	0.002 to 0.5 W/m•K
Specific Heat Capacity	Optional
High Thermal Conductivity Kit	Up to 2.5 W/m•K
Measurement Time	30 to 40 minutes
Reproducibility	± 0.5 to 1%
Accuracy	± 1 to 2%
HFM-100/HFM-50 Plate Temperature Range	-20 to 75°C (-4 to 167˚F)
HFM-100 HT Plate Temperature Range	-30 to 110 °C (-22 to 226˚F)
HFM-100 / HFM-100 HT Sample Size	Up to 300 x 300 x 100 mm (12 x 12 x 4 in)
HFM-50 Sample Size	Up to 200 x 200 x 50 mm (8 x 8 x 2 in)
Standard	ASTM C518, ASTM C1784, ISO 8301, JIS A1412, EN 12667, and EN 12664

Method is continually improved; specifications are subject to change without prior notice.
*Performance verified with NIST 1450d / 1450e
*Chilled circulator required

The Thermtest HFM-100 is capable of testing materials over a temperature range of -20 to 75°C (-4 to 167˚F). NIST 1450d, Fibrous Glass Board, is a certified Standard Reference Material from the National Institute of Standards, and Technology. Measured results are within 2% of the certified values.



With the added High Thermal Conductivity Kit, the HFM-100 / HFM-50 are able to accurately and efficiently measure higher thermal conductivity materials, such as glass and ceramics. For such applications, an external thermocouple kit is used in combination with the sample being tested. Macor, Quartz, and Pyrex were tested in the HFM from 10˚C to 60˚C (50˚F to 140˚F). All measured values are within the stated accuracy of the system, ± 5%.