Adquisición de datos de enfriamiento con termopar tipo k para probetas de acero inoxidable en la plataforma Arduino

In the present work, was made an experimental study in the acquisition of data of the temperature in a furnace brand Nobertherm P300 of resistance, using a thermocouple flexible K-Type using the platform, Arduino, and the processing of data is in the software matlab. It was used stainless steel cylindrical (1/2” diameter per 2” long) specimens as test material. The thermocouples were installed inside the probes in a depth of 1 inch, then were placed in the pre-heated furnace to 900 °C. The cooling process was carried out with water at room temperature for 20 seconds. Cooling data were monitored employing an Arduino Mega 2560 connected to thermocouple reading modules MAX 6675. The results obtained were six readings per second in the cooling period studied. This could be a comparable precision to commercial equipment. Also, the data processing was done on the Matlab® platform within an application, where the graphics generated from the different test will be shown.

TEMPERATURE RISE OF COLD-FORMED STEEL BUILT-UP BACK-TO-BACK COLUMN UNDER STANDARD FIRE

Cold-formed steel (CFS) has been used for various applications in building structure. Due to its many advantages, the uses of CFS can be widened to build new or to renovate existing single one or two families private homes. However, the fire resistance of the CFS is a critical issue whereby inclined to lose its vigour when it is exposed to fire, compared to hot-rolled steel member. This study takes the opportunity to investigate the application of this material as column members subjected to the standard fire. Four columns were tested. One column with a static load was tested under the ambient condition, while the three other columns were loaded at different degrees of utilisation under the standard ISO 834 fire conditions. The increases of temperature on the column surface were monitored using thermocouple Type K and the analyses of this thermocouple reading was taken to evaluate the mean temperature of the column. The temperature behaviours of back-to-back column for all degrees of utilisation showed that, the web was a lower temperature compared to the flange due to the greater thickness of the web. Meanwhile, the failure temperature of the CFS could reach up to 651.0 ºC for 30.0 % degree of utilisation with 8.0 minutes of resistant time.

Difference between Wafer Temperature and Thermocouple Reading during rapid Thermal Processing

ABSTRACTThermocouples are often used as a calibration standard for rapid thermal processing. Although it has been recognized that the thermocouple temperature can be different from the wafer temperature, the magnitude of the temperature difference is difficult to quantify. In this work, we present a simple analytical model to demonstrate the difference between the thermocouple temperature and the true wafer temperature. The results show that a large difference can exist between the thermocouple and the wafer temperature. This is because the optical and thermophysical properties of the thermocouple and the glue material are different from those of the wafer. The model results show that temperature measurement becomes more accurate if fine diameter thermocouple wires with very low emissivity are used.

Thermocouple Temperature Disturbances in Low Conductivity Materials

The axisymmetric transient heat conduction problem of a thermocouple embedded in a low thermal conductivity material is analytically investigated. The thermocouple is positioned normal to a surface which is heated by a time-variable heat flux. The results of the analysis are presented as dimensionless curves for a variation of several dimensionless parameters. The analysis may be used to calculate: (a) The temperature of a thermocouple temperature measurement for a known heat flux. (b) The undisturbed temperature at the location of the thermocouple junction from the transient thermocouple measurement. (c) The undisturbed heat flux just before thermocouple from the thermocouple measurement. It is found that the temperature disturbances in the thermocouple reading due to the presence of the thermocouple itself may be very large. It is shown that in certain cases the disturbance could be as large as 50 per cent of the temperature rise. An example is given in which the disturbance reaches 700 deg F.