Apparatus for Determining the Temperature of At Least One Fluid

Abstract

Provided is an apparatus for determining the temperature of at least one fluid. The apparatus includes an optical fiber. A first end of the optical fiber is connected to at least one fiber tip, and a first additional reflector is introduced into the at least one fiber tip at a first predetermined distance from an outer end of the at least one fiber tip. A second end of the optical fiber is connected to a processing apparatus. The processing apparatus includes an optical source. The optical source is configured to launch an optical signal into the optical fiber, and a coherent detector. The coherent detector is configured to determine the temperature of at least one fluid by receiving a first light signal that corresponds to parts of the optical signal that are reflected at the outer end of the at least one fiber tip when the at least one fiber tip is inserted into the at least one fluid and a second light signal that corresponds to parts of the optical signal that are reflected at the first additional reflector when the at least one fiber tip is inserted into the at least one fluid, determining a difference of the optical phases of the first light signal and the second light signal, and determining the temperature of the at least one fluid based on the difference of the optical phases of the first light signal and the second light signal.

Claims

1. An apparatus for determining the temperature of at least one fluid, wherein the apparatus comprises an optical fiber, wherein a first end of the optical fiber is connected to at least one fiber tip, and a first additional reflector introduced into the at least one fiber tip at a first predetermined distance from an outer end of the at least one fiber tip, and wherein a second end of the optical fiber is connected to a processing apparatus, wherein the processing apparatus comprises an optical source, wherein the optical source is configured to launch an optical signal into the optical fiber, and a coherent detector, wherein the coherent detector is configured to determine the temperature of at least one fluid by receiving a first light signal that corresponds to parts of the optical signal that are reflected at the outer end of the at least one fiber tip when the at least one fiber tip is inserted into the at least one fluid and a second light signal that corresponds to parts of the optical signal that are reflected at the first additional reflector when the at least one fiber tip is inserted into the at least one fluid, determining a difference of the optical phases of the first light signal and the second light signal, and determining the temperature of the at least one fluid based on the difference of the optical phases of the first light signal and the second light signal.

2. The apparatus according to claim 1, wherein the apparatus further comprises a second additional reflector that is introduced into the at least one fiber tip at a second predetermined distance from the first additional reflector.

3. The apparatus according to claim 2, wherein the coherent detector is configured to determine the temperature of the at least one fluid by receiving the first light signal, the second light signal and a third light signal that corresponds to parts of the optical signal that are reflected at the second additional reflector when the at least one fiber tip is inserted into the fluid, by determining a difference of the optical phases of the first light signal and the second light signal and a difference of the optical phases of the second light signal and the third light signal, and by determining the temperature of the at least one fluid based on the difference of the optical phases of the first light signal and the second light signal and the difference of the optical phases of the second light signal and the third light signal.

4. The apparatus according to claim 1, wherein the apparatus comprises a plurality of fiber tips, wherein the apparatus is configured in such a way that all fiber tips can simultaneously be inserted into a plurality of fluids in such a way that each of the plurality of fiber tips is inserted in a different one of the plurality of fluids, and wherein the signal processor is configured to determine the temperature of each of the plurality of fluids.

5. The apparatus according to claim 1, wherein the processing apparatus is a coherent optical time domain reflectometer.

6. A system for determining the temperature of at least one fluid, wherein the system comprises at least one fluid reservoir and an apparatus for determining the temperature of at least one fluid according to claim 1, wherein the apparatus for determining the temperature of at least one fluid is configured to determine the temperature of at least one fluid contained in the at least one fluid reservoir.

7. A method for determining the temperature of at least one fluid, wherein the method comprises the steps of: inserting at least one fiber tip into at least one fluid, wherein the at least one fiber tip is connected to an optical fiber, and wherein an additional first reflector is introduced into the at least one fiber tip at a first predetermined distance from an outer end of the at least one fiber tip; and determining the temperature of the at least one fluid through a processing apparatus connected to a second end of the optical signal, wherein the determining the temperature of the at least one fluid comprises launching an optical signal into the optical fiber, receiving a first light signal that corresponds to parts of the optical signal that are reflected at the outer end of the at least one fiber tip and a second light signal that corresponds to parts of the optical signal that are reflected at the first additional reflector, determining a difference of the optical phases of the first light signal and the second light signal, and determining the temperature of the at least one fluid based on the difference of the optical phases of the first light signal and the second light signal.

8. The method according to claim 7, wherein a second additional reflector is introduced into the at least one fiber tip at a second predetermined distance from the first additional reflector, and wherein the step of determining the temperature of the at least one fluid comprises the steps of: launching an optical signal into the optical fiber; receiving the first light signal, the second light signal and a third light signal that corresponds to parts of the optical signal that are reflected at the second additional reflector when the at least one fiber tip is inserted into the fluid; determining a difference of the optical phases of the first light signal and the second light signal and a difference of the optical phases of the second light signal and the third light signal; and determining the temperature of the at least one fluid based on the difference of the optical phases of the first light signal and the second light signal and the difference of the optical phases of the second light signal and the third light signal.

9. The method according to claim 7, wherein a plurality of fiber tips are simultaneously inserted into a plurality of fluids in such a way that each of the plurality of fiber tips is inserted in a different one of the plurality of fluids, and wherein the temperature of each of the plurality of fluids is determined by the processing apparatus.

10. The method according to claim 7, wherein the coherent detector is a coherent optical time domain reflectometer.

11. The apparatus according to claim 2, wherein the apparatus comprises a plurality of fiber tips, wherein the apparatus is configured in such a way that all fiber tips can simultaneously be inserted into a plurality of fluids in such a way that each of the plurality of fiber tips is inserted in a different one of the plurality of fluids, and wherein the signal processor is configured to determine the temperature of each of the plurality of fluids.

12. The apparatus according to claim 3, wherein the apparatus comprises a plurality of fiber tips, wherein the apparatus is configured in such a way that all fiber tips can simultaneously be inserted into a plurality of fluids in such a way that each of the plurality of fiber tips is inserted in a different one of the plurality of fluids, and wherein the signal processor is configured to determine the temperature of each of the plurality of fluids.

13. The apparatus according to claim 2, wherein the processing apparatus is a coherent optical time domain reflectometer.

14. The apparatus according to claim 3, wherein the processing apparatus is a coherent optical time domain reflectometer.

15. The apparatus according to claim 4, wherein the processing apparatus is a coherent optical time domain reflectometer.

16. The apparatus according to claim 11, wherein the processing apparatus is a coherent optical time domain reflectometer.

17. The apparatus according to claim 12, wherein the processing apparatus is a coherent optical time domain reflectometer.

18. The method according to claim 8, wherein a plurality of fiber tips are simultaneously inserted into a plurality of fluids in such a way that each of the plurality of fiber tips is inserted in a different one of the plurality of fluids, and wherein the temperature of each of the plurality of fluids is determined by the processing apparatus.

19. The method according to claim 8, wherein the coherent detector is a coherent optical time domain reflectometer.

20. The method according to claim 9, wherein the coherent detector is a coherent optical time domain reflectometer.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Embodiments of the invention will now be described with reference to the drawings,

[0032] FIG. 1 illustrates an apparatus for determining the temperature of at least one fluid according to embodiments of the invention;

[0033] FIG. 2 illustrates a flowchart of a method for determining the temperature of at least one fluid according to a first embodiment;

DESCRIPTION OF THE INVENTION

[0034] FIG. 1 illustrates an apparatus for determining the temperature of at least one fluid 1 according to embodiments of the invention.

[0035] During chemical or biological tests, for example a PCR (polymerase chain reaction) test, the temperature of a small amount of fluid needs to be measured. For example, during chemical or biological tests, it can be required to monitor the temperature change which accompanies a reaction. Therein, the accuracy and precision of the apparatus that is used to monitor the temperature are one of the main factors which affect such measurement.

[0036] During such chemical or biological tests, a small amount of fluid, for example 100 μl, is usually inserted into small wells, wherein a plurality of wells can be contained in a common plate, and wherein each well usually has a depth of approximately only 20 mm.

[0037] According to the embodiments of FIG. 1, an apparatus for determining the temperature of at least one fluid 1 is provided, wherein the apparatus 1 comprises an optical fiber 2, wherein a first end of the optical fiber 3 is connected to at least one fiber tip 4, and a first additional reflector 5 introduced into the at least one fiber tip 3 at a first predetermined distance from an outer end of the at least one fiber tip 6, and wherein a second end of the optical fiber 7, opposite the first end of the fiber tip 3, is connected to a processing apparatus 8, wherein the processing apparatus 8 comprises an optical source 9, wherein the optical source 9 is configured to launch an optical signal into the optical fiber 2, and a coherent detector 10, wherein the coherent detector 10 is configured to determine the temperature of at least one fluid and comprises a receiving device 11 that is configured to receive a first light signal that corresponds to parts of the optical signal that are reflected at the outer end of the at least one fiber tip 6 when the at least one fiber tip 4 is inserted into the at least one fluid and a second light signal that corresponds to parts of the optical signal that are reflected at the first additional reflector 5 when the at least one fiber tip 4 is inserted into the at least one fluid, a first determining device 12 that is configured to determine a difference of the optical phases of the first light signal and the second light signal, and a second determining device 13 that is configured to determine the temperature of the at least one fluid based on the difference of the optical phases of the first light signal and the second light signal.

[0038] When an optical signal, for example light, propagates in a medium, for example an optical fiber, the light wave undergoes a phase shift, wherein the phase shift can be defined as a function of the temperature. By further introducing a reference reflection, the accuracy of the determination of the temperature can be increased without having to costly amend the apparatus as such.

[0039] Thus, an improved apparatus for determining the temperature of at least one fluid 1 is provided.

[0040] Therein, the receiving device can for example be realized by a signal receiver. The first determining device and the second determining device can, for example, further be realized by code, that is stored in a memory and executable by a processor.

[0041] According to the embodiments of FIG. 1, a bare fiber tip, which has a length of approximately 10 mm, is used to probe the temperature of the fluid, which changes the refractive index of the corresponding fiber glass. Therein, the at least one fiber tip has been produced by cleaving the tip of the optical fiber 2 and removing the coating of the optical fiber over a section of about 10 mm.

[0042] Further, the first predetermined distance is approximately 10 mm, wherein the first additional reflector 5 has been introduced close to a transition between the at least one fiber tip 4 and the optical fiber 2, or close to the first end of the optical fiber 3, respectively, wherein the first additional reflector can for example be introduced by splicing, UV inscription, scrimping, e-beam writing, or any other known suitable method.

[0043] Therein, the corresponding phase change in the at least one fiber tip 4 is used as a measure for the temperature change based on the first additional reflector as measurement section.

[0044] Further, the optical source is configured in such a way that reflected signals from the fiber tip can be distinguished from additional reflection.

[0045] As shown in FIG. 1, the apparatus 1 further comprises a second additional reflector 14 that is introduced in the at least one fiber tip 4 at a predetermined distance from the first additional reflector.

[0046] For standard optical fibers the phase change over 10 mm and a temperature change of 8 K is approximately 27 and therefore, periodic over the temperature, wherefore in this case, the temperature determination is not unique anymore. For this purpose, a second smaller reflection is introduced into the fiber tip 4, wherein, according to the embodiments of FIG. 1, this second additional reflector 14 is introduced into the fiber tip 4 approximately 1 mm after the first additional reflector 5, and wherein the second additional reflector can again, for example, be introduced by splicing, UV inscription, scrimping, e-beam writing, or any other known suitable method.

[0047] Therein, the second additional reflector 14 is used to increase the range of unique measurements. According to the embodiments of FIG. 1, the processing apparatus 8 is configured to determine the temperature of the at least one fluid by launching an optical signal into the optical fiber, wherein the receiving device 11 is configured to receive the first light signal, the second light signal and a third light signal that corresponds to parts of the optical signal that are reflected at the second additional reflector 14 when the at least one fiber tip 4 is inserted into the fluid, wherein the first determining device 12 is configured to determine a difference of the optical phases of the first light signal and the second light signal and a difference of the optical phases of the second light signal and the third light signal, and wherein the second determining device 13 is configured to determine the temperature of the at least one fluid based on the difference of the optical phases of the first light signal and the second light signal and the difference of the optical phases of the second light signal and the third light signal.

[0048] Further, although only one fiber tip is shown in FIG. 1, the apparatus can also comprise a plurality of fiber tips, wherein the apparatus can be configured in such a way that all fiber tips can simultaneously be inserted into a plurality of fluids in such a way that each of the plurality of fiber tips is inserted in a different one of the plurality of fluids, and wherein the processing apparatus is configured to determine the temperature of each of the plurality of fluids. For example, this can be achieved by using a 1×N fiber coupler and lead fibers and/or time-multiplexing the signals from the individual fiber tips via delay lines.

[0049] According to the embodiments of FIG. 1, the processing apparatus 8 is further a coherent optical time domain reflectometer 15.

[0050] Using the apparatus shown in FIG. 1, the temperature of a small fluid amount of for example 100 μl can be determined with a small fiber tip 4 without interfering with the temperature of the fluid, wherein a high measurement or determination speed, respectively, is enabled.

[0051] FIG. 2 illustrates a flowchart of a method for determining the temperature of at least one fluid 20 according to embodiments of the invention.

[0052] As shown in FIG. 2, the method 20 comprises a step 21 of inserting at least one fiber tip into at least one fluid, wherein the fiber tip is connected to an optical fiber, and wherein an additional first reflector is introduced into the at least one fiber tip at a first predetermined distance from an outer end of the at least one fiber tip, and a step 22 of determining the temperature of the at least one fluid, wherein the step 22 of determining the temperature of the at least one fluid comprises a step 23 of launching an optical signal into the optical fiber, a step 24 of receiving a first light signal that corresponds to parts of the optical signal that are reflected at the outer end of the at least one fiber tip and a second light signal that corresponds to parts of the optical signal that are reflected at the first additional reflector, a step 25 of determining a difference of the optical phases of the first light signal and the second light signal, and a step 26 of determining the temperature of the at least one fluid based on the difference of the optical phases of the first light signal and the second light signal.

[0053] According to the embodiments of FIG. 2, a second additional reflector is introduced into the at least one fiber tip at a second predetermined distance from the first additional reflectometer, wherein in step 24, the first light signal, the second light signal and a third light signal that corresponds to parts of the optical signal that are reflected at the second additional reflector when the at least one fiber tip is inserted into the fluid are received, wherein in step 25, a difference of the optical phases of the first light signal and the second light signal and a difference of the optical phases of the second light signal and the third light signal is determined, and wherein in step 26, the temperature of the at least one fluid is determined based on the difference of the optical phases of the first light signal and the second light signal and the difference of the optical phases of the second light signal and the third light signal.

[0054] Further, according to the embodiments of FIG. 2, a plurality of fiber tips are simultaneously inserted into a plurality of fluids in step 21 in such a way that each of the plurality of fiber tips is inserted in a different one of the plurality of fluids, and wherein the method 20 further comprises determining the temperature of each of the plurality of fluids, or wherein step 23 of determining the temperature of the at least one fluid is separately executed for each of the wells, respectively.

[0055] Therein, the method for determining the temperature of at least one fluid 20 shown in FIG. 2 can for example be used to monitor or determine the temperature during a biological or chemical test.

REFERENCE SIGNS

[0056] 1 apparatus

[0057] 2 optical fiber

[0058] 3 first end

[0059] 4 fiber tip

[0060] 5 first additional reflector

[0061] 6 outer end

[0062] 7 second end

[0063] 8 processing apparatus

[0064] 9 optical source

[0065] 10 signal processor

[0066] 11 receiving device

[0067] 12 first determining device

[0068] 13 second determining device

[0069] 14 second additional reflector

[0070] 15 coherent optical time reflectometer

[0071] 20 method

[0072] 21 step

[0073] 22 step

[0074] 23 step

[0075] 24 step

[0076] 25 step

[0077] 26 step