Piezootporna sonda za merenje brzine u jednodimenzijskom nestišljivom strujanju

Abstract

Radeći na problemu kalibracije sondi sa zagrejanim vlaknima u okviru rada [3], javila se potreba za sondom kojom se može meriti trenutna brzina u jednodimenzijskom vazdušnom mlazu. Ubrzo potom na Mašinskom fakultetu u Beogradu je razrađena ideja o prvoj domaćoj piezorezistivnoj sondi kojom se meri trenutni diferencijalni pritisak. Sonda je realizovana u saradnji sa IHTM, Centrom za mikroelektronske tehnologije i monokristale. Probna ispitivanja su pokazala da se sonda može uspešno koristiti za merenje trenutne brzine jednodimenzijskog nestišljivog strujanja. U tom smislu je posle prvenac sonde napravljeno još nekoliko sličnih sondi. U radu su dati osnovni elementi tehnološkog postupka za dobijanje senzora pritiska. Pored detaljnog opisa senzorskog čipa ovde su prikazani i drugi elementi sonde JR-p. Pre svakog merenja sondom ona mora da se baždari. Sonda JR-p se baždari statički i u kvazistacionarnom vazdušnom mlazu. Ovde su prikazani rezultati jednog takvog baždarenja.

Working on the problem of calibration of hot wire probes within (3), we came to the need to have a probe for measuring the instantaneous velocity in a one-dimensional air jet. Soon after the idea concerned with the first domestic piezoresistant probe by means of which the instantaneous differential pressure can be measured was developed on the Faculty of Mechanical Engineering. The probe was realized in the collaboration with IHTM, the Center for microelectronic technology and monocrystals. First tests with the probe showed that it could be successfully used for measuring the instantaneous velocity in one-dimensional incompressible flows. In that sense, some more similar probes were produced after the pioneering one. In this paper the basic elements of the technological procedure for the production of the pressure sensor are given. In addition to a detailed description of the sensor chip we show here some other elements of the probe JR-p also. Before any use the probe must be calibrated. The probe JR-p is calibrated statically in a quasi-steady air jet. The results of such a calibration are presented here.