CS203699B1 - Pipe flowmeter - Google Patents

Description

The invention relates to a tubular flow meter for measuring air or gases, for example carbon dioxide, carbon monoxide, nitrogen and the like, in particular in the clinical practice, in the diagnosis of respiratory diseases, possibly in other areas,

Previously known flowmeters used in clinical practice are also of the tubular type. In order to induce the required pressure drop, it is necessary to insert either a sieve or a grid into the flow tube. In addition, when inhaling or exhaling into the flowmeter tube, when diagnosing the patient under examination, the water vapors contained in the exhaled air condense on the sieve or grid. This results in a change in the pneumatic resistance of these primers, causing erroneous lung function measurements. For this reason, it is necessary to electrically heat the sieve or the grill with a spiral heater to a temperature of about 37 ° C. The application of a sieve or grid has a considerable pneumatic resistance, thus, when examining the lungs, daches to the distorted data. A further drawback of the flow meters used hitherto is that turbulence occurs behind the sieve or grid at higher gas flows. This results in irregular oscillation of the membrane.

All these drawbacks are overcome by the flowmeter according to the invention, which consists in the fact that two connecting tubes are sealed into the flowmeter tube and the pressure gauge chamber. Capillaries are inserted into the connecting tubes.

The present invention simplifies the measurement of the flow of gaseous media in the sense that its construction and realization is simplified with respect to the prior art flowmeters, since it lacks sewn or non-sewn flowing media. grid, such as e.g. other respiratory flowmeters.

In the attached drawing, the diagram of the flowmeter e is a diaphragm 2 consisting of two connecting tubes 3 in which glass capillaries 6 are inserted. As a result of the application of the high-sensitivity diaphragm 2 made of silicone rubbers, the pressure drop β · P - - β, which occurs at the length of the length 5, is sufficient to sufficiently deform the diaphragm 2 of the pressure gauge 2. This can be achieved by changing its diameter 6 or by changing the length 5. Higher flow rates 6 result in considerable turbulence in the flow tube 7. This high turbulence is transmitted to the connecting tube 3 and causes oscillation of the specific diaphragm 2, the oscillation amplitude increasing with increasing flow. By inserting capillaries 4 into the connecting tubes 3, the transfer of turbulence to the membrane 2 is avoided. At whatever phase of the flowing amount of the gas to be measured, the membrane 2 remains in rest and no other fluctuations of stochastic character are transmitted to other parts of the electronic processing circuit.

The flowmeter according to the invention can be used, in particular, in clinical practice in the diagnosis of pathological lung conditions.

Claims (2)

OBJECT OF THE INVENTION Tubular flow meter, characterized in that two ends of the connecting tubes (3) are sealed into the flow tube (7) and the other two ends of the connecting tubes (3) are sealed into the pressure gauge body (1) and the capillaries are inserted into the connecting tubes (3) / 4 /.