Vplivi velikosti notranje prostornine tlačnega zaznavala na dinamične lastnosti merilnega sistema za tlak

Perme, Tim (author), Kutin, Jože (mentor)

Za merjenje zvezno spreminjajočega tlaka pogosto uporabljamo piezoelektrična zaznavala, povezana s cevko. Prostornina znotraj pokrovčka tlačnega zaznavala lahko odločilno vpliva na dinamične lastnosti merilnega sistema, v katerem se tlačni signal, ki ga izmerimo, razlikuje od merjenega tlaka. V tej nalogi smo ugotavljali lastnosti teh sistemov z različnimi pokrovčki ter cevkami, s katerimi smo obravnavali podkritično in nadkritično dušene sisteme. Izvajali smo meritve na dinamičnem generatorju tlaka z dvema piezoelektričnima zaznavaloma, kjer je bilo eno neposredno pritrjeno na generator za referenco in drugo povezano s cevko. Poleg tega pa smo izračunali karakteristike sistema še s teoretičnimi modeli. Meritve in teoretični modeli so se najbolj ujemali v sistemih s krajšimi cevkami, prostornina je na dušilne razmernike imela večji vpliv pri sistemih s cevkami z majhnim premerom ali krajšo dolžino.

• Language: Slovenian
• Keywords: meritve tlakov, vplivi volumnov, frekvenčne karakteristike, naravne frekvence, dušilni razmerniki, časovne konstante
• Work type: Final paper
• Typology: 2.11 - Undergraduate Thesis
• Organization: FS - Faculty of Mechanical Engineering
• Place of publishing: Ljubljana
• Publisher: [T. Perme]
• Year: 2019
• Number of pages: XIV, 23 f.
• PID: 20.500.12556/RUL-110493
• UDC: 531.787:681.2.08(043.2)
• COBISS.SI-ID: 16943643
• Publication date in RUL: 15.09.2019

Secondary language

• Language: English
• Title: Effects of the internal volume of a pressure sensor on the dynamic properties of a pressure measurement system

Abstract

Piezoelectric sensors with a connecting tube are often used for measurements of time varying pressure. The volume inside of the sensor cap can have a decisive effect on the properties of measurement system in which the pressure signal within the measured object differs from the measured one. Within this paper we have studied the properties of the systems with different sensor caps and connecting tubes in order to investigate the properties of both underdamped and overdamped systems. The measurements were made on a dynamic pressure generator with two piezoelectric sensors one of which was directly mounted on the generator as a reference and the other connected with a tube. Calculations based on theoretical models were also made. Theoretical models predicted the measured values well for shorter tubes and the internal volume of the cap had a larger effect on damping ratios when shorter tubes or tubes with smaller internal diameter were used.

• Keywords: pressure measurements, internal volumes, frequency characteristics, damping ratios, time constants