Ispitivanje nehomogenosti termoparskih osjetnika temperature

undergraduate thesis

• Title (english): Thermocouple inhomogeneity testing
• Author: Mislav Bogdan
• Mentor: Danijel Šestan (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2023-09-27, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering; Process Energy Engineering

Abstract

Termoparovi su uređaji koji se koriste za mjerenje temperature. Standardizirani su s obzirom na materijale koji tvore termoparske žice. Pritom, tipovi termoparova koji su najčešće u upotrebi su E, S, K, R, J i T. Primjenjivi su u širokom rasponu temperatura te su pogodni za mjerenja brzih promjena temperature. Termoparovi rade na principu termoelektričnog efekta koji se zove Seebeckov efekt koji omogućava da se zbog postojanja temperaturnog gradijenta duž termoparske žice inducira napon. Ovaj napon je moguće izmjeriti te ga pomoću usporedbenih tablica ili polinoma višeg stupnja pretvoriti u temperaturu. Generirani napon homogenog termopara ovisi samo o temperaturama krajeva termopara, dok je kod nehomogenog termopara on suma svih generiranih napona na svim neizotermalnim dijelovima žica. Kao posljedica ovoga, temperatura izmjerena nehomogenim termoparom odstupat će od stvarne temperature za određeni iznos. Nehomogenost je karakteristika termopara koja nastaje uslijed mehaničkih ili kemijskih oštećenja. Kako bi se odredio utjecaj nehomogenosti termopara, potrebno je provesti ispitivanje nehomogenosti.

Abstract (english)

Thermocouples are devices used for temperature measurement. They are standardized with respect to the materials that make up the thermocouple wires. In addition, the types of thermocouple wires that are most often used are E, S, K, R, J and T. They are applicable in a wide range of temperatures and are suitable for measuring quick temperature changes. Thermocouples work on the principle of a thermoelectric effect called the Seebeck effect, which allows voltage to be induced due to the existence of a temperature gradient along the thermocouple wire. This voltage can be measured and converted to temperature using reference tables or higher degree polynomials. The generated voltage of a homogeneous thermocouple depends only on the temperatures of the ends of the thermocouple. The generated voltage of an inhomogeneous thermocouple is the sum of all generated voltages on all non-thermal parts of the wires. Therefore, the temperature measured by the inhomogeneous thermocouple will deviate from the actual temperature by a certain amount. Inhomogeneity is a characteristic of thermocouples that occurs due to mechanical or chemical damage. In order to determine the influence of thermocouple inhomogeneity, it is necessary to perform an inhomogeneity test.

• Keywords: termopar; Seebeckov efekt; napon; temperatura; homogeni termopar; nehomogeni termopar; ispitivanje nehomogenosti
• Keywords (english): thermocouples; Seebeck effect; voltage; temperature; homogeneous thermocouple; inhomogeneous thermocouple; inhomogeneity test
• Language: croatian
• URN:NBN: urn:nbn:hr:235:277327
• Study programme: Title: Mechanical Engineering; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka strojarstva (sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka strojarstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2023-09-26 10:58:30