Measuring apparatus
A measuring device for determining the CO 2 content in the exhaled air of a living being, for example, a person or a mammal. The device may have a measuring tube defined by a wall, said measuring tube having an air inlet and an air outlet, with an inlet and an air outlet, with a CO 2 measuring device having a sensor pot which is in fluid communication with the measuring tube. The sensor pot extends through the wall of the measuring tube into the interior of the measuring tube, wherein the diameter of the measuring tube is reduced in the region of the sensor pot. The sensor pot is substantially open towards the measuring tube, such that the sensor pot is configured for direct measurement of the CO 2 content of air exhaled through the measuring tube, past the sensor pot.
1 . A measuring apparatus for determining a CO 2 content in the exhaled air of a living being including at least one of a person or a mammal, the apparatus comprising:
a housing defining an air inlet opening and an air outlet opening;
a wall disposed within the housing forming a virtual tube, and defining a measuring space within the virtual tube, wherein the measuring space is in communication with, and extends between, the air inlet opening and the air outlet opening;
a CO 2 -measuring device projecting laterally relative to the virtual tube, and which is in fluidic communication with the measuring space within the virtual tube, the CO 2 measuring device including a sensor pot; wherein
the sensor pot extends at least in part through the wall of the virtual tube into the measuring space within an interior area of the virtual tube, wherein a diameter of the measuring space is reduced in a region of the sensor pot;
the sensor pot is configured so as to be open towards the measuring space; and
the CO 2 -measuring device is arranged in the sensor pot and is configured to measure the CO 2 content of the air in the sensor pot directly.
2 . The measuring apparatus according to claim 1 , wherein the measuring space has a constant diameter over its entire length from the air inlet opening to the air outlet opening, except for a region where the diameter of the measuring space is reduced.
3 . The measuring apparatus according to claim 1 , wherein the ratio of a volume of the measuring space, disregarding the sensor pot, to a volume of the sensor pot is in the range of from 7:1 to 13:1.
4 . The measuring apparatus according to claim 1 , wherein the air inlet opening and the air outlet form opposite ends of the measuring space, and their prolongation configures the virtual tube as a straight virtual measuring tube.
5 . The measuring apparatus according to claim 4 , wherein the sensor pot is arranged substantially perpendicular to a longitudinal axis of the straight virtual measuring tube.
6 . The measuring apparatus according to claim 1 , wherein an infrared-based sensor is provided in the CO 2 -measuring device.
7 . The measuring apparatus according to claim 1 , wherein the CO 2 -measuring device is configured to carry out a continuous measurement.
8 . The measuring apparatus according to claim 1 , wherein the interior of the measuring space is configured such that air, apart from the sensor pot, is able to flow from the air inlet opening to the air outlet opening substantially without turbulence.
9 . The measuring apparatus according to claim 1 , wherein the measuring space has a U-shaped cross section.
10 . A method for determining the CO 2 content in the exhaled air of a living being, having a measuring apparatus according to claim 1 , wherein the living being exhales into the air inlet opening through the measuring space multiple times.
11 . The method according to claim 10 , wherein the CO 2 -measuring device carries out a continuous measurement of the CO 2 content.
12 . The method according to claim 10 , wherein at least 7 maximum values determined by the CO 2 -measuring device are stored.
13 . The method according to claim 10 , wherein at least the two lowest maximum values of a plurality of maximum values are disregarded in the final evaluation.
14 . The method according to any claim 10 , wherein there is outputted as the output value a mean, in particular an arithmetic mean, of a plurality of maximum values.
15 . The method according to claim 10 , wherein the measured values determined by the CO 2 -measuring device are provided with a correction factor.