Abstract: A method for determining the measurement value of a measurement quantity of a substance using a color indicator, the color indicator having at least one indicator field having previously been brought into contact with the substance, is characterized in that the color indicator and a color reference are visually sensed, the color reference having at least two reference fields of different colors, that an intermediate value of the measurement quantity is obtained with computer assistance based on the captured color values of the reference fields and the indicator field, and that the measurement value of the substance is obtained from this intermediate value.

Abstract: In measuring devices (1) including measuring sensors (2) on a distal end (3) of a shaft (4), it is also provided to configure at least one distance sensor (7, 8, 9) and/or an acceleration sensor (16) on this distal end (3), in order to enable an automatic distance measurement and/or determination of the position and/or the orientation of the measuring sensor (2) within a measuring range (6), and thus the recording of spatially resolved measured values.

Abstract: A method for determining the measurement value of a measurement quantity of a substance using a color indicator, the color indicator having at least one indicator field having previously been brought into contact with the substance, is characterized in that the color indicator and a color reference are visually sensed, the color reference having at least two reference fields of different colors, that an intermediate value of the measurement quantity is obtained with computer assistance based on the captured color values of the reference fields and the indicator field, and that the measurement value of the substance is obtained from this intermediate value.