The Experts below are selected from a list of 105 Experts worldwide ranked by ideXlab platform

Emile Webster - One of the best experts on this subject based on the ideXlab platform.

  • Trials of Pt-20%Rh versus Pt Thermocouples between 157 °C and 962 °C
    Metrologia, 2020
    Co-Authors: Emile Webster
    Abstract:

    For over a century the Type S (Pt-10%Rh) and R (Pt-13%Rh) Thermocouples have been used as primary or secondary reference thermometers. However, the measurement uncertainties of both types at the silver point (~962 °C) are typically limited to about 0.5 °C, due to drift caused by crystallographic ordering between 200 °C and 500 °C and rhodium oxidation between 500 °C and 900 °C. Although both processes can be reversed using an 1100 °C anneal, regular annealing can be inconvenient or impracticable. This paper follows up a prior study indicating that an alternative Noble-Metal Thermocouple comprised of Pt-20%Rh and Pt is relatively insensitive to both drift mechanisms. Four Thermocouples, assembled using wire from four different manufacturers, were evaluated using a gradient-furnace and homogeneity scanner. Measurements were also made using a salt-bath (200 °C to 500 °C) and fixed points between the indium and silver points. The experiments indicate that individual Thermocouples are stable at the silver point to within 0.18 °C for periods of up to 100 hours and all four Thermocouples have emf vs temperature characteristics within 0.3 °C of each other. This intrinsic stability and similarity, coupled with cost, assembly and use conditions identical to a Type R or S Thermocouple make the Pt-20%Rh vs Pt Thermocouple an attractive alternative. Recommended annealing procedures enabling the greatest stability are also given.

Fu Zhiyon - One of the best experts on this subject based on the ideXlab platform.

  • Proficiency testing for calibrating working Noble Metal Thermocouple
    China Measurement & Test, 2015
    Co-Authors: Fu Zhiyon
    Abstract:

    In order to understand the capability of working Noble Metal Thermocouple after implementation the JJG 141——2013 Verification Regulation of Working Noble Metal Thermocouple.China National Accreditation Service for Conformity Assessment(CNAS) organized the proficiency test of working Noble Metal Thermocouple.88 laboratories form 28 provinces/cities/municipals took part in the proficiency test.In this paper, the implementation process of the test was described,including project design,sample preparation,homogeneity stability test,result statistic and analysis,etc. The resulted showed that 98.86% laboratories have satisfactory results.In conclusion,most laboratories taking part in the proficiency test have good competence in calibrating working Noble Metal Thermocouple.

Rodney L. Waters - One of the best experts on this subject based on the ideXlab platform.

  • Laser welding of Noble Metal Thermocouple fine wires
    2018
    Co-Authors: Floyd R. Pothoven, Rodney L. Waters
    Abstract:

    This paper describes the development of a specialized laser system for welding fast response small bead Thermocouples. Fast response Thermocouple performance is predicated by a small mass Thermocouple junction. Up until now Thermocouple bead diameters have been on the order of three times the wire diameter and have subsequently suffered a slow response time. With the system described herein the bead diameter is kept to a nearly 1:1 relationship with the wire.This paper describes the development of a specialized laser system for welding fast response small bead Thermocouples. Fast response Thermocouple performance is predicated by a small mass Thermocouple junction. Up until now Thermocouple bead diameters have been on the order of three times the wire diameter and have subsequently suffered a slow response time. With the system described herein the bead diameter is kept to a nearly 1:1 relationship with the wire.

Floyd R. Pothoven - One of the best experts on this subject based on the ideXlab platform.

  • Laser welding of Noble Metal Thermocouple fine wires
    2018
    Co-Authors: Floyd R. Pothoven, Rodney L. Waters
    Abstract:

    This paper describes the development of a specialized laser system for welding fast response small bead Thermocouples. Fast response Thermocouple performance is predicated by a small mass Thermocouple junction. Up until now Thermocouple bead diameters have been on the order of three times the wire diameter and have subsequently suffered a slow response time. With the system described herein the bead diameter is kept to a nearly 1:1 relationship with the wire.This paper describes the development of a specialized laser system for welding fast response small bead Thermocouples. Fast response Thermocouple performance is predicated by a small mass Thermocouple junction. Up until now Thermocouple bead diameters have been on the order of three times the wire diameter and have subsequently suffered a slow response time. With the system described herein the bead diameter is kept to a nearly 1:1 relationship with the wire.