ISSN:
1573-9686
Keywords:
Fluidic gas sensor
;
Flueric sensors
;
Jet-edge resonator oscillator
;
Fluidic oscillator sensor
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
,
Technology
Notes:
Abstract A unique fluidic-electronic system utilizing flueric jet-edge resonator oscillator sensors has been developed to continuously measure concentrations of oxygen, carbon dioxide, halothane, enflurane, and nitrous oxide in respiratory and anesthetic gases. The sensing unit consists of two flueric jet-edge resonator oscillators operating in parallel. At a constant geometry, flow rate, and temperature, the frequency generated by these oscillators is a function of the molecular weight and specific heat of the gases flowing through them. Oscillator frequencies are detected by pressure transducers. These transducer signals are processed and converted electronically to a.d.c. voltage which is calibrated and displayed in units of constituent concentrations per voltage. The change in frequency of the sensing unit is linear for CO2 and O2 in air and for CO2, N2O, halothane, and enflurane in oxygen. The sensitivity of the sensors is approximately 65 Hz/%CO2 and 20 Hz/%O2 when referenced against air. For these same sensors, sensitivities for CO2, N2O, halothane, and enflurane are approximately 55 Hz/%CO2, 45 Hz/%N2O, 680 Hz/% halothane, and 790 Hz/%enflurane when referenced against oxygen. Time response for the sensor system is 450±10 msec from zero to 90% full scale.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02367000
Permalink
