The FOX 801 Heat Flow Meter is an accurate, easy-to-use instrument for measuring thermal conductivity according to ASTM C518 and ISO 8301. Capable to operate both in standalone or PC-controlled configurations, FOX 801 Heat Flow Meter provides rapid and accurate results. The instrument features proprietary thin film heat flux transducers, digital thickness measurements and responsive temperature control. A versatile instrument, it is especially well-suited to measuring slices of cellular plastics.
- Solid state cooling/heating
- Thickness measurement to 0.025 mm
- Two Thin-Film Heat Flux Transducers
- Suitable for R&D and QC testing
- WinTherm software for full PC control and datahandling
Statistics Sheet for FOX 801
FOX 800 models in their different configurations comply with ASTM C518, ISO 8301, ASTM 1784, EN 12664, and JIS A 1412 Standards
|Maximum Sample Thickness||304mm (12″)|
|Sample Size||762x762mm (30 sq. in.)|
|Temperature Range||-10 °C to 65 °C|
|Temperature Control Accuracy||±0.01 °C|
|Absolute Thermal Conductivity Accuracy||±1%|
|Thermal Conductivity Range||0.001 to 0.35 W/m K |
(0.007 to 2.4 BTU in/hr ft2 °F)
0.001 to 2.5 W/m K
(0.007 to 17.3 BTU in/hr ft2 °F)
|Heat Flux Transducers Area||254 x 254mm (10 sq. in.)|
- Measurement Technique
- Advanced Heat Flux Measurement
- Precision Temperature Control
- Complete Thermal Conductivity Solution
Samples are placed between two plates in the test stack and a temperature gradient is established over the thickness of the material. The plates may be positioned either to a user-defined thickness, or using AutoThickness, in which the instrument automatically moves to establish contact with the sample. In-situ sample thickness is measured with four optical encoders, one at each corner of the plate, providing stable measurements to within 0.025 mm.
Advanced Heat Flux Measurement
At the heart of the measurement is the LaserComp Heat Flux Transducer, designed and manufactured specifically and exclusively for thermal conductivity measurements. The Heat Flux Transducer integrates over the entire active area (254x254mm / 10 sq. in.) to provide a truly representative measurement of the total heat flow. Overall transducer thickness is less than 1 mm, precluding heat flow distortion. A type E thermocouple is bonded in the center of each transducer and both are sealed to ensure consistent precision over the life of the instrument. Because each thermocouple is positioned within 0.1 mm of the sample surface, they provide truly representative readings of the sample’s surface temperature (± 0.01 °C resolution) and heat flux. The same thermocouples are also used for plate temperature control.
Precision Temperature Control
The FOX series Heat Flow Meters achieve accurate, stable thermal equilibrium quickly through a combination of intimate sample temperature measurement, low mass solid state elements and advanced temperature control electronics.
Plate temperature control is based on the same responsive thermocouples in close sample contact as are used for the sample heat flux measurement. An advanced temperature control algorithm monitors the plate temperatures 20 times per second and rapidly brings the system to the selected equilibrium test condition. Plate temperature is controlled to within 0.01 °C by a digital signal processor. A multistage PID algorithm ensures temperature control which is responsive, stable, and prevents set-point overshoot. To achieve this, heater power output from the solid state elements is adjusted every 0.5 s.
Both the top and bottom plates can be heated or cooled, allowing for testing with heat flow up or down. The low thermal mass design of the plates combined with the power of the DSP and power output board enable extremely fast attainment of set-points.
Complete Thermal Conductivity Solution
The FOX series Heat Flow Meters can be operated as either stand-alone instruments, or coupled to a PC for test set-up and data storage. The WinTherm software package is a user-friendly tool for setting experimental parameters, viewing real-time test results, storing, and analyzing data. In either operational mode, the instrument electronics detect equilibrium according to defined conditions, automatically proceeding to the next programmed measurement temperature after a final value is collected. Specific heat measurements are also available, with data collection and calculation guided by the WinTherm software.
- External Thermocouple Kit
- Rotational System
External Thermocouple Kit
Thermocouples are attached directly to the sample surfaces, eliminating the impact of interface resistance, and improving the measurement accuracy for higher thermal conductivity samples (up to 2.5 W/m K). In case of rigid specimens the external thermocouples can be also placed in grooves machined in the sample. Instruments configured for this option feature auxiliary outlets for the external thermocouples.
The FOX 801 Heat Flow Meter can be configured with the innovative Rotational System from LaserComp. Understanding the complex combination of heat transfer mechanism present in field installations, the Rotational System allows to measure thermal conductivity under conditions matching real-life material’s orientation. The rugged system allows the motorized rotation of the test system to a user-defined angle between 0° and 90°. This allows for the exact, representative, simulation of conditions present in roofs, walls, skylights, and more.
The Multi-Transducer design provides users with measurements of thermal conductivity at different locations in their samples. The measurements from the multi-transducer also help to check how homogeneous their samples are.
The Multi-Transducer is a 300mm (12”) squared area bonded to the center of each instruments plate. The five 100 mm (4”) squared measuring areas are arranged in an X pattern.
The WinTherm software provides an easy graphical way to select which heat flux transducers are to be used during each test. Any number of heat flux transducers with their associated thermocouples can be selected. The WinTherm displays the total average thermal conductivity as well as each individual measurement for thermal conductivity in each location.