The Transient Plane Source-Effusivity (TPS-EFF) is a portable meter that uses a single-sided TPS sensor with test times of 2 and 10 seconds to understand the measurement of comfort with touch time fully.
Best For Textiles, Fabrics, and Solids
ASTM D7984-16
Standard Test
Method
-10°C To 50°C
Temperature
Range
Thermal Effusivity (W√s/m2K) is described as the ability of a material to exchange heat with its surroundings. When you touch a material, heat leaves your hand and goes into the material. If a small amount of heat leaves your hand, the material will feel warm (low effusivity). If a large amount of heat leaves your hand, the material will feel cold (high effusivity).
As the measured thermal effusivity of textiles and fabrics encompasses various modes of heat transport (conductivity, convection and, radiation), the results are referred to as thermal effusance. The measurement of solids, where the main heat transport property is thermal conductivity, results are properly referred to as thermal effusivity.
Features and Capabilities
Mathematically, thermal effusivity equates to the square root of the product of thermal conductivity (W/m•K), Density (kg/m3) and Heat Capacity (J/kg•K). For certain materials, like textiles, there are often other modes of heat transfer, such as convection and radiation. These modes of heat transfer alter the thermal conductIVITY to thermal conductANCE. The resulting term used for measurement of materials like this is referred to as Thermal Effusance.
- Follows International Standard ASTM D7984-16
- Portable, Economical, and Accurate
- Easy to use
- Test time 2 and 10 seconds
- No user calibrations required
Specification
| Materials | Textiles, Fabrics and Solids |
| Measurement Capabilities | 1-Dimensional |
| Thermal Effusivity Range | 35 to 1700 W√s/m2K |
| Measurement Time | 2 and 10 seconds |
| Reproducibility | 2% |
| Accuracy | 5% |
| Temperature Range1 | -10 to 50°C |
| Minimum Sample Size | 35 mm diameter x thickness dependent on Effusivity |
| Maximum Sample Size | Unlimited |
| Moisture Range | 0 to 90% (non-condensing) |
| Sensor Diameter | 30 mm |
| Standards | ASTM D7984-16 |
| Test Method | Transient Plane Source (TPS) |
Standard TPS-EFF Sensor
The TPS-EFF comes with a standard 30 mm diameter single-sided sensor for testing textiles, fabrics, and solids. The spring-loaded sensor can be used in two testing configurations. The first is with the sample on top of the sensor. The second configuration is the sensor on top of the sample. At the push of a button, samples can be measured at 2 and 10 second test times. The additional 10 second test time allows for superior characterization of materials feeling of warmth or coolness.
Compression, Humidity and Temperature
Several applications and environmental specific conditions can affect the thermal effusivity (feeling of warmth or coolness) of a material. When used with a compression stand and environmental chamber, the TPS-EFF can measure the effect of compression, humidity, and temperature on a materials thermal effusivity.
Sample Measurements
The Sample
Using the TPS-EFF, samples of unlimited size can be tested; the sample should be at least 30 mm in diameter to allow contact with the TPS-EFF sensor. Measurement of various textiles, fabrics, and solids are possible. Care should be taken to ensure sufficient thickness of the sample, and the divergence technique may be used to confirm this.
Approximate Time: < 1 minute
Place Sample on Sensor
Once a sample has been prepared, measurements may be configured in one of two ways; sample placed on top of the sensor or sensor placed on top of the sample.
Approximate Time: < 1 minute
Measurement
From the portable TPS-EFF, a test time of 2 or 10 seconds may be selected. The test activated with the push of a button.
Approximate Time: < 2 minute
Result Calculations
Upon completion of tests, temperature and thermal effusivity results are displayed on the screen. Results can then be exported from the TPS-EFF to Excel, via Micro-SD or USB.
Approximate Time: 1 minute
Applications
Thermal Effusivity of Multiple Layers and Force
Discovering the feeling decays with test time (touch time) as heat from the sensor (your skin) is dominated by the lower effusivity layer when a more effusive layer is placed over a more insulative layer and measured.
Testing Thermal Effusivity with Force
Testing Thermal effusivity of Memory Foam with a compression force of 1 lb and 2 lb
Thermal Conductivity and Viscosity of Carbon Black Heat Transfer Nanofluids
Thermal Conductivity and Viscosity of Carbon Black Heat Transfer Nanofluids
THERMAL EFFUSIVITY METER ACCESSORIES
TPS-EFF Compressor Stand
Used to compress materials for testing with the TPS-EFF to mimic real situations
TPS-EFF Powder Adaptor
For testing small particle sediment and sand to measuring thermal effusivity.
