Method of operating an optochemical sensor

A method for operating a device that optochemically senses an analyte, the device comprising a radiation source that emits radiation of a first and a second predetermined intensity, a detector, and a sensitive element that comprises a signal substance based upon the analyte, the method comprising the steps of:

• a) contacting the sensitive element with the analyte, effecting interaction of the signal substance therewith;
• b) determining a first raw signal, representing a function of the analyte content at a first point in time, by exciting the signal substance with radiation of the first predetermined intensity, generating a signal that is collected by the detector;
• c) determining a subsequent raw signal, representing a function of the analyte content at a subsequent point in time, by exciting the signal substance with radiation of one of the predetermined intensities, generating a signal that is collected by the detector;
• d) calculating at least one comparison value that depends on at least two of the raw signals;
• e) comparing the calculated comparison value to at least one predetermined limit value and adjusting the radiation intensity on this basis:
• if the calculated comparison value is greater than or equal to the predetermined limit value, the radiation source is set at the first predetermined intensity;
• or
• if the comparison value is smaller than the predetermined limit value and the analyte content is essentially stable, the radiation source is set at the second predetermined intensity, which is lower that the first intensity (I1);
• and
• f) reiterating the steps c) to e) until a termination criterion is met.