Projekt sustava za umjeravanje mjerila vakuuma

master's thesis

• Title (english): Project of a vacuum gauge calibration system
• Author: Lucija Sabljić
• Mentor: Lovorka Grgec-Bermanec (mentor)
• Granter: University of Zagreb; Faculty of Mechanical Engineering and Naval Architecture; Zagreb
• Defense date and country: 2022-12-15, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Mechanical Engineering; Process Energy Engineering

Abstract

U ovom radu prikazano je umjeravanje mjerila vakuuma na temelju projektiranog
mjernog sustava za usporedbeno umjeravanje. Opisana je podjela mjerila vakuuma s obzirom
na područje mjerenja (grubi, srednji, visoki, ultra visoki vakuum), način mjerenja (direktno,
indirektno) te izvedbu mjerila (analogni, digitalni). Za što bolju točnost mjerila potrebno je
izvršiti umjeravanja uređaja. Umjeravanje podrazumijeva postupak kojim se uspoređuje stvarna
veličina mjerenja umjerenog uređaja i veličina određena standardom (etalon). Kolika je točnost
mjerila iskazuje se izračunom odstupanja i mjerne nesigurnosti očitanih vrijednosti. Mjerna
nesigurnost prikazuje raspon vrijednosti unutar kojega se nalazi prava vrijednost mjerne
veličine.
Eksperimentalni dijelom na temelju projektiranog mjernog sustava prikazana su
umjeravanja dvaju ispitivanih mjerila tlaka: analognog mehaničkog (s Bourdonovom cijevi) i
digitalnog Pirani vakuumetra. Ispitivana mjerila tlaka umjeravala su se s obzirom na etalonsko
mjerilo tlaka – digitalni Pirani. Proračunom i analizom rezultata dobivenih mjerenjem
izračunata su i grafički prikazana odstupanja i mjerne nesigurnosti u ovisnosti o tlaku etalona.
Povećanjem tlaka etalona, povećava se vrijednost odstupanja, a time i vrijednost mjerne
nesigurnosti pojedine ispitivane točke mjerila tlaka. Analogni Bourdonov vakuumetar
umjeravao se u području od 0 do 130 mbar dok digitalni Pirani vakuumetar od 10-2
do 100
mbar. Pogreška svakog od ispitivanog mjerila tlaka je unutar 5-10%, a uzroci netočnosti su
razni faktori kao što su uvjeti okoline, rezolucija, pomak, kut očitanja vrijednosti analognih
mjerila tlaka i dr.

Abstract (english)

This thesis presents the vacuum gauges calibration based on the designed measured
system for comparative calibration. Described vacuum gauges can be divided according to the
measurement range (rough, medium, high, ultrahigh vacuum), measurement method (direct,
indirect) and gauge performance (analog, digital). For the best gauge accuracy, it is necessary
to implement device calibration. Calibration implies a procedure that compares the calibrated
gauges actual measurement value and the value determined by the standard. Vacuum gauge
accuracy is shown by calculating the deviation and measurement uncertainty of recorded
values. Measurement uncertainty values range is determined within the measured true value
quantity.
In the experimental part, based on the designed measuring system, the two tested
calibrations pressure gauges were presented: the mechanical (with Bourdon tube) and the digital
Pirani vacuum gauge. The tested pressure gauges were calibrated with reference to the standard
pressure gauge - digital Pirani. The measurement results are calculated and analysed obtained
and the deviations and measurement uncertainties in dependence on the standard pressure are
calculated and presented graphically. By increasing the standard pressure, the deviation value
also increases, and thus the measurement uncertainty value of the individual pressure gauge
tested point. The analog Bourdon vacuum gauges was calibrated in the range from 0 to 130
mbar, while the digital Pirani vacuum gauges was calibrated from 10-2
to 100 mbar. The tested
pressure gauges error is within 5-10%, and the inaccuracy causes are various factors such as
environmental conditions, resolution, displacement, reading angle of analog pressure gauges,
etc.

• Keywords: mjerila vakuuma; umjeravanje mjerila vakuuma; mjerna nesigurnost
• Keywords (english): vacuum gauges; calibration of vacuum gauges; uncertainty
• Language: croatian
• URN:NBN: urn:nbn:hr:235:850717
• Study programme: Title: Mechanical Engineering; specializations in: Design, Process and Energy Engineering, Production Engineering, Engineering Modelling and Computer Simulation, Marine Engineering, Industrial Engineering and Management, Materials Engineering, Mechatronics and Robotics, Autonomous Systems; Course: Process and Energy Engineering; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka strojarstva (magistar/magistra inženjer/inženjerka strojarstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2022-11-30 21:09:12