Sensor arrangements and methods of operating a sensor arrangement
According to various embodiments, there is provided a sensor arrangement including a filter configured to provide an output signal having an output wavelength, the output wavelength having a dependence on a temperature of the filter; a temperature module configured to change the temperature of the filter; a controller circuit configured to control the temperature module for changing the temperature of the filter until the output wavelength increases with decreasing temperature; and a determination circuit configured to determine a dew point of an environment surrounding the sensor arrangement, based on a minimum value of the output wavelength and the dependence.
1. A sensor arrangement comprising:
a filter configured to modulate an electromagnetic wave at least partially based on a temperature of the filter;
a temperature control module configured to change the temperature of the filter;
a controller circuit configured to control the temperature control module to change the temperature of the filter until a wavelength of the modulated electromagnetic wave increases with decreasing temperature after reaching a minimum value; and
a determination circuit configured to determine a dew point of an environment surrounding the sensor arrangement, based on the minimum value of the wavelength.
2. The sensor arrangement of claim 1 , wherein the wavelength decreases with decreasing temperature when the temperature of the filter is above the dew point.
3. The sensor arrangement of claim 1 , wherein the wavelength increases with decreasing temperature when the temperature of the filter is below the dew point.
4. The sensor arrangement of claim 1 , further comprising a wavelength meter configured to measure the wavelength.
5. The sensor arrangement of claim 1 , further comprising a recorder configured to record the wavelength.
6. The sensor arrangement of claim 1 , further comprising a computation circuit configured to compute, a relative humidity of the environment based on the dew point.
7. The sensor arrangement of claim 1 , wherein the determination circuit is further configured to determine the minimum value of the wavelength.
8. The sensor arrangement of claim 1 , wherein the wavelength of the modulated electromagnetic wave has a first linear dependence on the temperature of the filter when the temperature of the fitter is below the dew point and wherein the wavelength of the modulated electromagnetic wave has a second linear dependence on the temperature of the filter when the temperature of the filter is above the dew point.
9. The sensor arrangement of claim 1 , wherein the determination circuit is configured to determine the dew point, further based on an initial temperature of the environment.
10. The sensor arrangement of claim 1 , wherein the filter is an optical filter.
11. The sensor arrangement of claim 1 , wherein the filter is a microelectromechanical systems device.
12. The sensor arrangement of claim 1 , wherein the filter comprises a waveguide.
13. The sensor arrangement of claim 1 , wherein the filter comprises at least one of a resonator, an interferometer or a photonics crystal structure.
14. The sensor arrangement claim 1 , wherein the filter comprises at east on of a microring resonator or a disk resonator.
15. The sensor arrangement of claim 1 , wherein the filter comprises at least one of a Mach-Zehnder interferometer or a Michelson interferometer.
16. The sensor arrangement of claim 1 , wherein the temperature control module changes the temperature of the filter monotonically.
17. The sensor arrangement of claim 1 , wherein the temperature control module comprises a cooler unit.
18. The sensor arrangement of claim 1 , wherein the filter comprises a waveguide configured to modulate the electromagnetic wave, wherein a refractive index of the waveguide is dependent on the temperature of the filter.
19. A method of operating a sensor arrangement, the method comprising:
modulating an electromagnetic wave at least partially based on a temperature of a filter;
changing the temperature of the filter using a temperature module;
controlling the temperature module to change the temperature of the filter until the wavelength increases with decreasing temperature after reaching a minimum value using a controller circuit; and
determining a dew point of an environment surrounding the sensor arrangement, based on the minimum value of the wavelength.
20. A sensor arrangement comprising:
a filter configured to modulate an electromagnetic wave at least partially based on a temperature of a filter,
wherein a wavelength of the modulated electromagnetic wave depends on the temperature of the filter, the dependence comprising a proportionality constant;
a temperature control module configured to change the temperature of the filter;
a controller circuit configured to control the temperature control module to change the temperature of the filter until the proportionality constant changes from a first value to a second value; and
a determination circuit configured to determine a dew point of an environment surrounding the sensor arrangement, based on the temperature of the filter when the proportionality constant changes from the first value to the second value.