| 摘要 |
In a method for detecting a variation, such as a variation in the concentration of a substance, in a flowing medium, a sample of the medium is made to flow past a sensor for detecting the variation, with the direction of flow of the sample being reversed and the velocity of the sample in relation to the sensor being reduced during passage of the sample through the sensor. A device for detecting such a variation contains a sensor and a pump controlled to reverse the direction of flow and to reduce the velocity of the sample of the medium for making a measurement of the sample. |
