Characteristic Curves of Iridium-Rhodium Sensing Elements in High-Temperature Transducer Applications

In order to increase the capacity and efficiency factor of gas turbines and internal combustion engines while preserving their high reliability, the gas temperature and its distribution need to be measured in combustion chambers. Values of these temperatures can exceed 1800°С in an oxidizing atmosphere. Therefore, designing temperature transducers for measurements in such severe environments, special attention should be paid to the selection of thermometric materials. The requirements of the necessary accuracy and temperature range over 1800°С in an oxidizing atmosphere are fulfilled only by the temperature transducer based on iridium-rhodium alloys. The characteristic curve of such sensing elements is individual and each temperature transducer is to be calibrated. The paper discusses a technique of determining the individual characteristic curve of iridium-rhodium sensing elements of high-temperature transducers. The preparation steps to be taken prior to the calibration and the main stages of determining the characteristic curve are described. The general view of the experimental set for calibrating the sensing elements is presented. Based on the calibration results, the form of approximating polynomial of the individual characteristic curve is proposed.

Temperature transducer with frequency output made in LTCC technology

Purpose The purpose of this study is to design a simple and cheap temperature transducer with frequency output with high measurement resolution in low temperature co-fired ceramic (LTCC) technology by using the distributed Resistance-Capacitance (RC) networks in high-pass filter configuration. Design/methodology/approach This paper presents the concept of elaboration of a transducer of temperature into frequency, its implementation in LTCC technology and test results. Construction and technological works are supported by a series of computer simulations of the process of indirect adjustment of the whole system. Findings The investigation results of the proposed and developed system have confirmed the correctness of the adopted concept, and the practical usefulness of an applied original method of indirect adjusting of the transducer. Practical implications The study contains practical and useful information about the principles of designing and manufacturing of the converters of the different physical quantities into frequency by using the elements with distributed parameters made in LTCC technology which was presented on the example of a temperature transducer. Originality/value The study presents the original solution of a simple transducer with the use of RC structures with distributed parameters made in LTCC technology and the idea of indirect adjustment of the elements to a desired value.