ASTM D is a significantly updated version of the Standard Test Method for Determination of Thermal Conductivity of. Soils and Rock by Thermal Needle . ASTM D – Standard Test Method for Determination of Thermal Conductivity of Soil and Soft Rock by Thermal Needle Probe Procedure. This standard is. Buy ASTM D TEST METHOD FOR DETERMINATION OF THERMAL CONDUCTIVITY OF SOIL AND SOFT ROCK BY THERMAL.
|Published (Last):||18 March 2014|
|PDF File Size:||9.39 Mb|
|ePub File Size:||7.67 Mb|
|Price:||Free* [*Free Regsitration Required]|
Measuring Principle | TK04 Thermal Conductivity Meter
The new Mini Asfm is a 50 mm long needle probe with a diameter of 2 mm for small samples. It can be used where standard size probes are too large for the available sample dimensions. This includes compressible materials like soil samples which cannot be tested with the already available Mini HLQ for plane surfaces. Use the Mini VLQ for samples with a minimum diameter of 40 mm and c5334-08 minimum length of 60 mm.
The Mini VLQ has a measuring range of 0. TK04 uses the well-established transient line source method widely known as needle probe method according to ASTM D A long and thin heating source the needle probe is inserted into a sample and is heated with constant power while recording the temperature rise with time inside the source.
The slower the source temperature rises, the r5334-08 is the thermal conductivity of the sample material. The thermal conductivity of the sample is calculated from the temperature rise with time registered by the probe.
Chosing an evaluation method is a compromise: The most common approximation method calculates thermal conductivity fron the slope of a straight line fitted to the measuring data.
Mathematically more complex approximations d533408 the form of the temperature curve more closely than a straight line.
They yield more accurate results, and they can be used to detect disturbances in the data by comparing the measured temperature curve to the theoretical curve form. This improves reliability significantly, because thermal conductivity measurements are very sensitive to sample preparation problems and satm measuring conditions.
As hard or brittle sample materials are often difficult to prepare for inserting a conventional needle probe, our modified method uses a needle embedded in the underside of a disk-shaped probe body which is just placed on top of the sample surface probe for sstm surfaces.
Soil Thermal Resistivity Meter – TLS – ASTM D – Thermtest Inc.
TK04 can use both methods by simply changing the connected probe. When using the modified method, part of the heat generated during measuring penetrates into the probe body instead of the sample material. A correction method developed by TeKa uses the thermal parameters of probe and sample to automatically determine the effective amount of heat entering into the sample material.
This ensures d5334-08 results for the conventional and the modified needle probe method in the complete measuring range.
The probes are calibrated x5334-08 by the manufacturer before delivery. The method then yields absolute thermal conductivity values without requiring any time-consuming reference or comparison measurements.
TK04 comes with a reference material for checking the operating condition of instrument and probes from time to time. Mini VLQ now available. Highly Accurate Evaluation Method The thermal conductivity of the sample is calculated from the temperature rise with time registered by the probe.