Utility of the hot-wire spirometer.

extrapolation of calibration curve of hot-wire spirometer using a novel neural network based approach

hot-wire spirometer uses a constant temperature anemometer (cta) for its operation. the working principle of cta, used for the measurement of fluid velocity and flow turbulence, is based on convective heat transfer from a hot-wire sensor to a fluid being measured. the calibration curve of a cta is nonlinear and cannot be easily extrapolated beyond its calibration range. therefore, a method for ...

Evaluation of a new electronic spirometer: the vitalograph "Escort" spirometer.

BACKGROUND The "Escort" spirometer is a lightweight, hand held spirometer employing a Fleisch pneumotachograph. Measurements of forced expiratory volume in one second (FEV1), forced vital capacity (FVC), and peak expiratory flow (PEF) are obtained from a single FVC manoeuvre. Results are displayed on a small liquid crystal display, but there is no graphical display. The performance of the Escor...

Hot-wire anemometry for superfluid turbulent coflows.

We report the first evidence of an enhancement of the heat transfer from a heated wire to an external turbulent coflow of superfluid helium. We used a standard Pt-Rh hot-wire anemometer and overheat it up to 21 K in a pressurized liquid helium turbulent round jet at temperatures between 1.9 K and 2.12 K. The null-velocity response of the sensor can be satisfactorily modeled by the counterflow m...

Characteristics of the Vitalograph spirometer.

Relation Between Wire Resistance and Fluid Pressure in the Transient Hot-Wire Method

The resistance of metals is a function of applied pressure, and this dependence is large enough to be significant in the calibration of transient hot-wire thermal conductivity instruments. We recommend that for the highest possible accuracy, the instrument's hot wires should be calibrated in situ. If this is not possible, we recommend that a value of γ, the relative resistance change with press...