SENSOR WITH ADJUSTMENT UNIT

Description

[0001] The invention relates to a sensor, which is in particular a position sensor and which has a detection unit for detecting a measured variable and for generating a measurement signal which represents the detected measured variable, as well as an adaptation unit for the measured variable or the measurement signal.

[0002] The measurement signal from sensors that capture a specific measured value has a signal-to-noise ratio that can fluctuate significantly when the sensor's ambient conditions, such as temperature and humidity, change. To reduce these fluctuations in the signal-to-noise ratio, many sensors use filters, such as adaptive filters.

[0003] However, the use of such filters increases the latency of the measurement signals, for example, in position sensors. This is undesirable in many position sensor applications. For example, during acceleration processes, the use of filters can cause undesirable position deviations. Furthermore, if the filter used is not an adaptive filter, the fluctuation in the signal-to-noise ratio can be reduced, but such filters do not allow the signal-to-noise ratio to be kept as constant as possible when the environmental conditions of the sensor change.

[0004] CH 702 140 A2 describes a sensor and a method for controlling a measurement signal of such a sensor, which incorporate temperature compensation. The sensor detects the temperature as a measured variable and generates a corresponding measurement signal. Temperature compensation involves detecting an indicator of an ambient condition of the sensor in the form of a temperature measurement. The sensor's measurement signal is adjusted using the temperature compensation output signal to achieve a high signal-to-noise ratio.

[0005] US 2003 / 0135314 A1 describes a sensor and a method according to a similar technology in which temperature compensation is carried out for a measurement signal of a sensor in order to reduce the noise of the measurement signal.

[0006] EP 3 671 105 B1 describes a sensor and a method according to a similar technology.

[0007] One object of the invention is to provide a sensor whose measurement signal has a signal-to-noise ratio that is as constant as possible under changing environmental conditions of the sensor.

[0008] This object is achieved by a sensor having the features of claim 1. Advantageous developments of the invention are specified in the subclaims, the description, and the drawings.

[0009] The sensor, which is in particular a position sensor, comprises a detection unit and an adaptation unit. The detection unit is designed to detect a measured variable and generate a measurement signal that represents the detected measured variable. The adaptation unit is designed to determine at least one indicator for at least one environmental condition of the sensor and to adjust a manipulated variable that influences the measured variable based on the at least one indicator for the at least one environmental condition of the sensor such that a ratio of the measurement signal generated by the detection unit and a noise of the measurement signal lies within a predetermined range and is constant regardless of the at least one environmental condition.

[0010] The indicator for the at least one environmental condition of the sensor can be determined, for example, by directly detecting one or more environmental conditions of the sensor, such as the ambient temperature or the humidity in the environment. However, the indicator can also be determined indirectly, for example, by monitoring the gain of an amplification device of the adaptation unit following a change in the at least one environmental condition or by detecting the ratio of the measurement signal to the noise of the measurement signal, since this ratio depends on the environmental conditions.

[0011] The manipulated variable that influences the measured variable can, for example, be a gain within the adaptation unit, which thus increases or decreases the measured signal according to the determined ambient condition in order to keep the ratio of the measured signal to its noise, or the signal-to-noise ratio of the measured signal, within the predetermined range. However, the manipulated variable can also be a signal for a device that directly influences the measured variable and thus the measured signal. For example, in an optical position sensor, the magnitude of the measured signal can be changed by changing a current supplied to a light source of the optical position sensor.

[0012] The sensor according to the invention is characterized in that, by adjusting the manipulated variable based on one or more determined ambient conditions, the measured variable and thus the measured signal are adapted to the ambient conditions in such a way that the ratio of the measured signal to its noise, or the signal-to-noise ratio of the measured signal, is kept within the predetermined range and remains virtually constant. In other words, the adaptation unit reduces or avoids fluctuations in the signal-to-noise ratio of the measured signal. Filtering of the measured signal is therefore no longer necessary or only required to a limited extent, so that the measured signal is no longer subject to the negative effects of filtering or is only subject to a correspondingly limited extent. For example, additional latency that would occur due to filtering the measured signal can be reduced or at least avoided.In certain applications that use the sensor's measurement signal, interference due to a fluctuating signal-to-noise ratio of the measurement signal can be suppressed.

[0013] According to one embodiment, the adaptation unit can further be designed to determine the at least one indicator for the at least one environmental condition of the sensor in such a way that at least one state variable, in particular a temperature and / or a humidity, of an environment of the sensor is measured by means of the sensor itself or by means of an external device, and to adjust the manipulated variable based on the measured state variable in such a way that an amount of the measurement signal is adjusted directly or indirectly.

[0014] The external device can, for example, be a thermometer or a humidity meter that provides a measurement signal to the adjustment unit. The magnitude of the measurement signal can, for example, be directly adjusted by changing a gain within the adjustment unit in accordance with a change in the measured ambient condition or conditions. An indirect adjustment of the measurement signal can be achieved by changing a signal or, for example, a current for another device whose output directly influences the measurement variable detected by the sensor. For example, the measurement signal of an optical position sensor can be adjusted by changing a current for a light source that illuminates a receiving unit of the position sensor.In this embodiment, the signal-to-noise ratio of the measurement signal can thus be kept in the predetermined range and, in particular, constant by measuring the ambient condition and adapting the measurement signal accordingly.

[0015] The adaptation unit may comprise an amplification device, and the manipulated variable may comprise a gain of the amplification device with which the adaptation unit amplifies the measurement signal. In other words, the measurement signal and thus the signal-to-noise ratio are directly influenced by adjusting the gain of the amplification device within the adaptation unit based on the determined at least one environmental condition.

[0016] Furthermore, the at least one indicator for the at least one ambient condition of the sensor can be formed in that the gain of the amplification device has a change characteristic that is at least similar to that of the at least one ambient condition. In such an embodiment, the gain of the amplification device can simultaneously form both the indicator for the at least one ambient condition, which changes according to the ambient condition and, for example, follows the temperature, and also represent the manipulated variable for adjusting the measurement signal.

[0017] In this embodiment, the measurement signal can thus exhibit self-compensation with respect to the changing ambient conditions, since the amplification of the measurement signal can follow the changing ambient conditions. The amplification device can, for example, comprise a resistor with a positive temperature coefficient (PTC resistor), in which the magnitude of the resistance changes such that the amplification is proportional to the temperature. In this embodiment, the magnitude of the measurement signal is thus automatically adjusted proportional to the change in the at least one ambient condition.

[0018] According to a further embodiment, the at least one indicator can comprise the ratio of the measurement signal generated by the detection unit to the noise of the measurement signal. In other words, in this embodiment, the indicator can be the signal-to-noise ratio itself, which is detected by the adaptation unit. The adaptation unit can, for example, detect the magnitude of the measurement signal and an amplitude of the noise of the measurement signal and relate them to one another to determine the signal-to-noise ratio of the measurement signal and thereby the indicator for the at least one environmental condition.

[0019] The adaptation unit can further be configured to cyclically detect the noise of the measurement signal by determining a standard deviation of the measurement signal. Based on the noise of the measurement signal detected in this way, the adaptation unit can determine the signal-to-noise ratio of the measurement signal in order, on the one hand, to keep it within the predetermined range by adjusting the manipulated variable and, on the other hand, to form the indicator for the at least one environmental condition in the embodiment described above.

[0020] Alternatively or additionally, the adaptation unit can be designed to set a bandwidth of a signal processing unit for the measurement signal of the sensor based on the at least one indicator such that the ratio of the measurement signal to the noise of the measurement signal lies within the predetermined range. The signal processing unit can be part of the adaptation unit and can be designed as an analog signal processing unit. In contrast to some of the above embodiments, in which the measurement signal itself is adapted in order to keep the signal-to-noise ratio as constant as possible, the signal-to-noise ratio in the present embodiment is influenced by the magnitude of the noise being adaptively adjusted by changing the bandwidth of the signal processing unit. In other words, in this embodiment, adaptive filtering of the measurement signal can take place, which can be adapted to the at least one environmental condition.However, the bandwidth for the signal processing unit can be adjusted in such a way that an increase in the latency of the measurement signal can be avoided.

[0021] The sensor may comprise an angle sensor or a linear position sensor, which may in particular be an optical angle sensor or an optical linear position sensor. According to a further embodiment, in such optical sensors, the manipulated variable may comprise a current supplied to a light source of the optical angle sensor or the optical linear position sensor. Furthermore, the adjustment unit may be configured to adjust the current based on the indicator for the at least one environmental condition.

[0022] In this embodiment, the measurement signal of the optical sensor can thus be indirectly adapted to the at least one ambient condition based on the current for the light source in order to keep the signal-to-noise ratio of the measurement signal in the predetermined range.

[0023] Alternatively, the sensor may comprise a magnetic, capacitive, or inductive angle sensor, or a magnetic, capacitive, or inductive linear position sensor. Similar to optical sensors, the magnetic properties, capacitances, or inductances of such sensors can be adjusted in accordance with the at least one environmental condition in a similar manner as described above for the light source current of optical sensors.

[0024] The invention further relates to a method for controlling a measurement signal of a sensor, in particular a position sensor. According to the method, a measured variable is detected by the sensor, and a measurement signal is generated that represents the detected measured variable. Furthermore, at least one indicator for at least one environmental condition of the sensor is determined. A manipulated variable that influences the measured variable is adjusted based on the at least one indicator for the at least one environmental condition of the sensor such that a ratio of the measured signal to a noise of the measured signal lies within a predetermined range and is constant regardless of the at least one environmental condition.

[0025] The statements regarding the sensor apply accordingly to the method, particularly with regard to advantages and preferred embodiments. Furthermore, it is understood that all features mentioned herein can be combined with one another, unless explicitly stated otherwise.

[0026] According to one embodiment of the method, the at least one indicator for the at least one environmental condition of the sensor is determined in such a way that at least one state variable, in particular a temperature and / or a humidity, of an environment of the sensor is measured by means of the sensor or an external device, and the manipulated variable can be adjusted on the basis of the measured state variable in such a way that an amount of the measurement signal is adjusted directly or indirectly.

[0027] The sensor may comprise an amplification device for the measurement signal, and adjusting the manipulated variable may comprise adjusting a gain of the amplification device with which the measurement signal is amplified or changing it with at least a similar characteristic to the at least one ambient condition.

[0028] Furthermore, the ratio of the generated measurement signal and the noise of the measurement signal can be detected in order to form the at least one indicator of the at least one environmental condition.

[0029] The invention is described below by way of example using an advantageous embodiment with reference to the accompanying figures. They show, schematically: Fig. 1 shows an exemplary sensor and Fig. 2 shows three different block diagrams illustrating the setting of a desired signal-to-noise ratio.

[0030] Fig. 1 As an example of a sensor according to the invention, FIG. 1 shows a schematic overview of a position sensor embodied as an optical encoder 100. The optical encoder 100 has an illumination unit 110, which includes a light source 112 with a light-emitting diode (LED), and a modulation device 120. The illumination unit 110 emits light in the direction of the modulation device 120.

[0031] The modulation device 120 has a modulation unit or a modulator 122, which comprises a bar pattern which is Fig. 1 is indicated by a dashed line. The modulation device 120 is illuminated with the light emitted by the illumination device 110. The line pattern can, for example, have light and dark areas, with the light being able to penetrate the light areas.

[0032] The sensor or optical encoder 100 further comprises a measuring or detection unit 130, which has at least two receiver diodes or photodiodes 132, 134. The receiver diodes 132, 134 are designed to receive the light emitted by the illumination unit 110 and transmitted through the modulation device 120. The detection unit 130 or its receiver diodes 132, 134 output a respective electrical measurement signal representing the intensity of the received light.

[0033] The encoder 100 further includes an adaptation unit 140, which receives the electrical signal from the detection unit 130 or the measurement signals from the respective receiver diodes 132, 134. The electrical signals transmitted from the receiver diodes 132, 134 to the adaptation unit 140 are amplified by the adaptation unit 140 to output a suitable output signal from the adaptation unit 140 to an evaluation unit 150.

[0034] The evaluation unit 150 is provided for determining a relative or absolute position of the modulation unit 122 based on the amplified signals of the receiver diodes 132, 134. When the modulation unit 122 moves, i.e., is displaced, the light intensity passing through the modulation device 120 is sinusoidally modulated. The line pattern of the modulation unit 122 is designed such that the electrical signals of the receiver diodes 132, 134 are phase-shifted relative to one another. Based on these phase-shifted electrical signals of the receiver diodes 132, 134, the evaluation unit 150 determines a displacement of the modulation unit 122 and, taking into account a reference mark (not shown), an absolute position of the modulation unit 122.

[0035] The Fig. 1 The optical encoder 100 shown is thus designed as a linear position sensor. However, if the optical encoder 100 is designed as a rotary encoder, in which the modulation unit 122 is located, for example, on a motor shaft, a rotational position of the motor shaft can be determined using the optical encoder or rotary encoder 100.

[0036] The adaptation unit 140 is further connected to an external device 160 for signaling purposes, which is designed to detect environmental conditions of the

[0037] Sensor 100. The ambient conditions include, for example, a temperature and / or humidity in the environment of the sensor or encoder 100, as well as, if necessary, other variables that determine the conditions of the sensor 100 in its environment. Thus, the external device 160 is provided for detecting the ambient conditions such as temperature and / or humidity in the environment of the sensor 100.

[0038] When the ambient conditions of the sensor 100 change, the noise of the sensor's measurement signals, i.e., the noise of the measurement signals output by the receiver diodes 132, 134, also changes. For example, the noise of these signals may increase as the temperature in the environment of the sensor 100 increases. Thus, the signal-to-noise ratio of one or more measurement signals output by the sensor 100 may improve or worsen, i.e., increase or decrease, as the ambient conditions of the sensor 100 change. However, a deterioration in the signal-to-noise ratio of the output signals of the sensor 100 is undesirable in many cases and may disrupt other applications that rely on the measurement signals of the sensor 100.

[0039] According to the invention, the adaptation unit 140 is therefore provided to keep the signal-to-noise ratio of the one or more measurement signals of the sensor 100 as constant as possible. In other words, the adaptation unit 140 ensures that the signal-to-noise ratio of the measurement signals of the sensor 100 lies within a predetermined range.

[0040] In the embodiment shown in Fig. 1 As shown, the adjustment unit 140 receives signals from the external device 160 that reflect the ambient conditions of the sensor 100. The adjustment unit 140 receives, for example, one or more signals that indicate the temperature and / or humidity in the environment of the sensor 100. The adjustment unit 140 is further connected to the light source or LED 112 of the illumination unit 110 of the sensor or optical encoder 100 in order to control the current supplied to the light source 112.

[0041] For this purpose, the adjustment unit 140 outputs a control signal 170 to the lighting unit 110, which corresponds to the change in the ambient conditions detected by the external device 160. The control signal 170 changes, for example, proportionally to the temperature and / or humidity detected by the external device 160 and output by the latter in the form of corresponding signals to the adjustment unit 140. Based on the control signal 170, the lighting unit 110 changes the current for the light source or LED 112 according to the change in the ambient conditions, i.e., the change in temperature and / or humidity. For example, if the ambient temperature increases, the control signal 170 causes the LED current for the light source or LED 112 to increase.

[0042] This increases the light intensity output by the illumination unit 110, so that the receiver diodes 132, 134 receive more light and output correspondingly larger signals. The increase in the measurement signals output by the receiver diodes 132, 134 improves the signal-to-noise ratio, which is ultimately output by the adaptation unit 140 to the evaluation unit 150. Fig. 1 In the embodiment of the sensor 100 shown, the signal-to-noise ratio of the measurement signal output by the sensor 100 is thus indirectly kept within a predetermined range or as constant as possible by increasing or decreasing the current for the LED or light source 112 according to the ambient conditions, ie according to the temperature and / or the humidity.

[0043] The Fig. 1 The embodiment shown therefore corresponds to an inventive procedure for setting or keeping constant the signal-to-noise ratio of the one or more measurement signals of a sensor 100, as this procedure is shown schematically in Fig. 2 shown in line "A". The ambient conditions 210, for example the temperature in the vicinity of the sensor, are detected by means of the external device 160 or by means of the sensor 100 itself. A measuring and control unit of the sensor 100, which may comprise, for example, the detection unit 130 and the adaptation unit 140 of the embodiment of Fig. 1 detects the ambient conditions or receives signals for them, such as measured values for the temperature and / or humidity in the environment of the sensor 100. This is in Fig. 2 represented in line "A" by the arrow pointing from the measuring and control unit 220 to the left toward the ambient conditions 210. The measuring and control unit 220 thus receives or records one or more measured variables that reflect the ambient conditions of the sensor 100.

[0044] Subsequently, the measuring and control unit 220 performs a signal adaptation 230, as described above for the embodiment of Fig. 1 described as an example. In this embodiment, corresponding to line "A" of Fig. 2 the measuring and control unit 220 sends the control signal 170 (cf. Fig. 1 ) to the illumination unit 110 in order to increase or decrease the current for the light source or LED 112 according to a change in the ambient conditions, such as temperature. This in turn increases or decreases the measurement signals output by the receiver diodes 132, 134. By increasing or decreasing the measurement signals of the receiver diodes 132, 134, the signal-to-noise ratio of the final measurement signal of the sensor 100 is increased or decreased according to the ambient conditions in order to keep the signal-to-noise ratio as constant as possible, as shown in Fig. 2 is indicated schematically at 240. The dashed arrow between 230 and 240 is intended to indicate that a nearly constant signal-to-noise ratio is the consequence of the signal adaptation 230.

[0045] Alternatively or additionally, the signal adaptation 230 according to the embodiment of row "A" of Fig. 2 can be carried out directly by adapting an amplification circuit in the adaptation unit 140 directly to the fluctuating ambient conditions 210. In this case, a bandwidth of a signal processing in the adaptation unit 140 can also be adapted according to the ambient conditions, for example, in the case of analog signal processing, the bandwidth of a low-pass or a band-pass filter. In this embodiment, the signal adaptation 230 is not carried out or only partially carried out via the control signal 170, which is provided for adjusting the current supplied to the LED or light source 112 in the embodiment of Fig. 1 Therefore, the control signal 170 is in Fig. 1 represented by a dashed line, which is intended to indicate that the control signal 170 represents only one of several possibilities for carrying out the signal adaptation 230.

[0046] In an alternative embodiment shown in row "B" in Fig. 2 As shown, the adaptation unit 140 comprises a signal amplification circuit 250, which has the same or at least a similar characteristic as one or more environmental conditions that influence the noise of the measurement signal of the sensor 100. In this embodiment, the signal amplification circuit 250 can, for example, comprise a diode with a corresponding forward characteristic or a resistor with a positive temperature coefficient (PTC resistor), the characteristic or resistance of which changes with temperature in the same or similar manner as the noise of the measurement signal output by the sensor 100.

[0047] In the embodiment of line "B" of Fig. 2 Thus, there is no direct detection of the ambient conditions 210. Instead, the ambient conditions 210 change at least one characteristic within the signal amplification circuit 250 in the same way as they change the noise of the measurement signal of the sensor 100. This results in an automatic adjustment or self-compensation of the signal strength of the measurement signal output by the sensor 100, which is, for example, proportional to the change in the ambient conditions.

[0048] The signal adaptation 230 is thus carried out in the embodiment according to line "B" of Fig. 2 automatically because the ambient conditions 210 influence one or more characteristics of the signal amplification circuit 250. The automatic adjustment of the signal strength, in turn, keeps the signal-to-noise ratio of the measurement signal of the sensor 100 as constant as possible or within a predetermined range, as shown at 240.

[0049] The fact that the ambient conditions 210 influence the signal amplification circuit 250 without the ambient conditions 210 being detected by a measurement is shown by the dashed arrow between 210 and 250. Likewise, the connection between the external device 160 and the adaptation unit 140 is shown in Fig. 1 shown in dashed lines, since the ambient conditions in the embodiments according to lines "B" and "C" of Fig. 2 not be recorded by the sensor 100 or the external device 160 in the form of one or more measured variables. In Fig. 2 The dashed arrows between the signal adaptation 230 and the most constant signal-to-noise ratio 240 indicate that the most constant signal-to-noise ratio 240 is a consequence of the signal adaptation 230.

[0050] In a further alternative embodiment shown in row "C" of Fig. 2 As shown, the signal-to-noise ratio itself serves as a measurement or control variable in order to keep it as constant as possible. For this purpose, the measurement and control unit 220 detects or measures the noise 260 of one or more measurement signals of the sensor 100, for example, the noise of the signals output by the receiver diodes 132, 134. For example, the adaptation unit 140 can be configured to cyclically detect the noise of the measurement signals based on determining a standard deviation of the measurement signals.

[0051] The noise 260 is in turn influenced by the environmental conditions 210, as indicated by the dashed arrow between the blocks 210 and 260 in arrows "C" of Fig. 2 The measuring and control unit 220 then determines the corresponding signal-to-noise ratio based on the one or more measurement signals and the noise 260 and uses this for the signal adaptation 230. The signal adaptation 230 can be carried out directly or indirectly as described above in connection with Fig. 1 or line "A" of Fig. 2 described.

[0052] Specifically, in this embodiment, the signal-to-noise ratio, which is determined based on the noise 260, is used as a controlled variable to either indirectly adjust the magnitude of the measurement signals of the sensor or the receiver diodes 132, 134 by adjusting the current for the LED 112 using the control signal 170, or to adjust the gain of an amplification circuit within the adaptation unit and / or the bandwidth of a signal processing unit within the adaptation unit according to the detected signal-to-noise ratio as a controlled variable. In the embodiment according to line "C," the signal adjustment 230 using the signal-to-noise ratio as a controlled variable thus in turn ensures that the signal-to-noise ratio of the measurement signal ultimately output by the sensor 100 is as constant as possible or lies within a predetermined range, as is determined by block 240 in Fig. 2 is shown. Bezugszeichenliste

[0053] 100Sensor, optical encoder 110Illumination unit 112Light source with light-emitting diodes (LEDs) 120Modulation device 122Modulation unit or modulator 130Detection unit 132, 134Receiver diode 140Adaptation unit 150Evaluation unit 160External device for detecting the ambient conditions 170Control signal 210Ambient conditions 220Measurement and control unit 230Signal adaptation 240Constant signal-to-noise ratio 250Signal amplification circuit 260Noise

Claims

1. A sensor (100), in particular a position sensor, preferably an angular sensor or a linear sensor, comprising: a detection unit (130) which is configured to detect a measurement variable and to generate a measurement signal which represents the detected measurement variable, and an adjustment unit (140) which is configured to determine at least one indicator for at least one environmental condition of the sensor (100) and to set a manipulated variable, which influences the measurement variable, based on the at least one indicator for the at least one environmental condition of the sensor (100) such that a ratio of the measurement signal generated by the detection unit (130) and a noise of the measurement signal is in a predetermined range and is in this respect constant irrespective of the at least one environmental condition.

2. A sensor (100) according to claim 1, wherein the adjustment unit (140) is further configured: to determine the at least one indicator for the at least one environmental condition of the sensor (100) such that at least one state variable, in particular a temperature and / or a humidity, of an environment of the sensor (100) is measured by means of the sensor (100) or an external device (160), and to set the manipulated variable based on the measured state variable such that a magnitude of the measurement signal is adjusted directly or indirectly.

3. A sensor (100) according to claim 1 or 2, wherein the adjustment unit (140) comprises an amplification device, and the manipulated variable comprises an amplification of the amplification device with which the adjustment unit (140) amplifies the measurement signal.

4. A sensor (100) according to claim 3, wherein the at least one indicator is formed in that the amplification of the amplification device has an at least similar change characteristic to the at least one environmental condition.

5. A sensor (100) according to any one of the preceding claims, wherein the at least one indicator comprises the ratio of the measurement signal generated by the detection unit and the noise of the measurement signal.

6. A sensor (100) according to any one of the preceding claims, wherein the adjustment unit (140) is configured to cyclically detect the noise of the measurement signal based on the determination of a standard deviation of the measurement signal.

7. A sensor (100) according to any one of the preceding claims, wherein the adjustment unit (140) is further configured to set a bandwidth of a signal processing unit for the measurement signal of the sensor (100) based on the at least one indicator such that the ratio of the measurement signal and the noise of the measurement signal is in the predetermined range.

8. A sensor (100) according to any one of the preceding claims, wherein the sensor (100) comprises an angle sensor or a linear position sensor.

9. A sensor (100) according to claim 8, wherein the sensor (100) comprises an optical angle sensor or an optical linear position sensor.

10. A sensor (100) according to claim 9, wherein the manipulated variable comprises a current which is supplied to a light source (112) of the optical angle sensor or the optical linear position sensor, and the adjustment unit (140) is further configured to set the current based on the indicator.

11. A sensor (100) according to claim 8, wherein the sensor (100) comprises a magnetic, capacitive or inductive angle sensor or a magnetic, capacitive or inductive linear position sensor.

12. A method for controlling a measurement signal of a sensor (100), in particular a position sensor, wherein the method comprises that: a measurement variable is detected by means of the sensor (100) and a measurement signal is generated that represents the detected measurement variable, at least one indicator for at least one environmental condition of the sensor is determined, and a manipulated variable, which influences the measurement variable, is set based on the at least one indicator for the at least one environmental condition of the sensor (100) such that a ratio of the measurement signal and a noise of the measurement signal is in a predetermined range and is in this respect kept constant irrespective of the at least one environmental condition.

13. A method according to claim 12, wherein the at least one indicator for the at least one environmental condition of the sensor (100) is determined such that at least one state variable, in particular a temperature and / or a humidity, of an environment of the sensor (100) is measured by means of the sensor (100) or an external device, and the manipulated variable is set based on the measured state variable such that a magnitude of the measurement signal is adjusted directly or indirectly.

14. A method according to claim 12 or 13, wherein the sensor (100) comprises an amplification device for the measurement signal, the setting of the manipulated variable comprises that an amplification of the amplification device, with which the measurement signal is amplified, is set or changes with an at least similar characteristic to the at least one environmental condition.

15. A method according to any one of the claims 12 to 14, wherein the ratio of the generated measurement signal and the noise of the measurement signal is detected to form the at least one indicator of the at least one environmental condition.