Utility model content
The purpose of this utility model is, the technical matters such as solve that traditional fiber temp sensor device is complicated, detection range is short and operating temperature range is narrow.
The purpose of this utility model and solve its technical matters and realize by the following technical solutions.
A kind of fibre optic temperature sensor, comprise optical transceiver module, Transmission Fibers and optical temperature sensing element, described optical transceiver module comprises light source, fiber coupler, the polarizer and temperature signal demodulating unit, described fiber coupler comprises the first port, the second port and the 3rd port, described first port directly receives the light that described light source sends, described second port connects the described polarizer, and described 3rd port connects described temperature signal demodulating unit; Described Transmission Fibers connects the described polarizer and described optical temperature sensing element; The light exit side mask of described optical temperature sensing element has total reflection film.
In the utility model one better embodiment, described optical temperature sensing element is optical crystal, birefringent optical glass or hi bi birefringence fiber.
In the utility model one better embodiment, described optical crystal is right cylinder or rectangular parallelepiped.
In the utility model one better embodiment, described birefringent optical glass is right cylinder or rectangular parallelepiped.
In the utility model one better embodiment, described light source is light emitting diode, super-radiance light emitting diode or semiconductor laser.
In the utility model one better embodiment, described fiber coupler is single-mode optical-fibre coupler, multi-module optical fiber coupler or polarization-maintaining fiber coupler.
In the utility model one better embodiment, the described polarizer is the optical fiber polarizer.
In the utility model one better embodiment, described Transmission Fibers is polarization maintaining optical fibre.
In the utility model one better embodiment, described polarization maintaining optical fibre is panda optic fibre or elliptical fiber.
In the utility model one better embodiment, described temperature signal demodulating unit comprises a photodetector and processes temperature signal system.
Compared to prior art, the temperature signal of the fibre optic temperature sensor that the utility model provides adopts Optical Fiber Transmission, long transmission distance, can reach 400 meters to several kilometers far away; Optical temperature sensing element is as sensing head, and its package dimension is little, site installation test simple and convenient; The demodulator circuit of temperature signal demodulating unit is simple and reliable, can not produce various electromagnetic wave signal to external world, therefore can not disturb other similar components and parts; Further, the operating temperature range of the fibre optic temperature sensor that the utility model provides is wide, between subzero 40 degrees Celsius to 250 degrees Celsius.
Above-mentioned explanation is only the general introduction of technical solutions of the utility model, in order to technological means of the present utility model can be better understood, and can be implemented according to the content of instructions, and can become apparent to allow above and other object of the present utility model, feature and advantage, below especially exemplified by preferred embodiment, and coordinate accompanying drawing, be described in detail as follows.
Embodiment
For the ease of understanding the utility model, below with reference to relevant drawings, the utility model is described more fully.Better embodiment of the present utility model is given in accompanying drawing.But the utility model can realize in many different forms, is not limited to embodiment described herein.On the contrary, provide the object of these embodiments be make to disclosure of the present utility model understand more thorough comprehensively.
Unless otherwise defined, all technology used herein and scientific terminology are identical with belonging to the implication that those skilled in the art of the present utility model understand usually.The object of the term used in instructions of the present utility model herein just in order to describe concrete embodiment, is not intended to be restriction the utility model.Term as used herein " and/or " comprise arbitrary and all combinations of one or more relevant Listed Items.
Please refer to Fig. 1, Fig. 1 is the principle schematic of the fibre optic temperature sensor that the utility model embodiment provides.
Fibre optic temperature sensor comprises optical transceiver module 10, Transmission Fibers 20 and optical temperature sensing element 30.
Optical transceiver module 10 comprises light source 101, fiber coupler 102, the polarizer 103 and temperature signal demodulating unit 104.
Light source 101 can be light emitting diode (LightEmittingDiode, be called for short LED), super-radiance light emitting diode ((SuperluminescentDiode, be called for short SLD) or semiconductor laser (LaserDiode is called for short LD).
Fiber coupler 102 can be single-mode optical-fibre coupler, multi-module optical fiber coupler or polarization-maintaining fiber coupler.Fiber coupler 102 comprises the first port A, the second port B and the 3rd port C, and the first port A directly receives the light that light source 101 sends, and the second port B connects the polarizer the 103, three port C and connects temperature signal demodulating unit 104.
The polarizer 103 can be polaroid or the optical fiber polarizer, and the present embodiment adopts the optical fiber polarizer.
Transmission Fibers 20 connects the polarizer 103 and optical temperature sensing element 30.Transmission Fibers 20 is polarization maintaining optical fibre, such as, be panda optic fibre or elliptical fiber.
Optical temperature sensing element 30 is the element that the birefringence of optical transmission carrier and the characteristic of temperature correlation can be utilized to realize the measurement to temperature, such as optical crystal, birefringent optical glass or all kinds of hi bi birefringence fiber.Wherein, optical crystal can be processed into right cylinder or rectangular parallelepiped, and birefringent optical glass can be processed into right cylinder or rectangular parallelepiped.The present embodiment adopts rectangular parallelepiped birefringent optical glass as optical temperature sensing element.Optical temperature sensing element 30 is encapsulated in sensing head, and sensing head one end is without any active device.
Refer to Fig. 2, for making the light reflected light transceiver module 10 of beam incident optical temperature-sensing element 30, the present embodiment is at the light exit side face 301 vacuum evaporation total reflection film 303 of optical temperature sensing element 30.Total reflection film 303 to the polarized light of incidence without additional polarization effect.
In the present embodiment, temperature signal demodulating unit 104 comprises a photodetector 41 and processes temperature signal system 42, and photodetector 41 only has one, can receive all linearly polarized lights returned and carry out light intensity mensuration.
In the fibre optic temperature sensor 1 that the present embodiment provides, the trend of light is: the light sent by light source 101 becomes linearly polarized light after fiber coupler 102, the optical fiber polarizer 103, and described linearly polarized light is beam incident optical temperature-sensing element 30 after polarization maintaining optical fibre 20 transmits.After two component temperature influences of linearly polarized light on the birefringence axis of optical temperature sensing element 30, its propagation constant changes, and then cause two bundle orhtogonal linear polarizaiton light to produce phase differential on the birefringence axis of optical temperature sensing element 30, phase differential has modulated light intensity, linearly polarized light after modulation is totally reflected through total reflection film 303 again, enters temperature signal demodulating unit 104 through the 3rd port C of polarization maintaining optical fibre 20, the optical fiber polarizer 103, fiber coupler 102.Intensity signal is detected by photodetector 41, then according to the temperature of the relation determination dut temperature parameter between light intensity-phase differential-temperature, and export tested parameter test result by processes temperature signal system 42.Test result is that numeral exports, can by industry standard platform Protocol Design interface.
Temperature signal demodulating unit 104 also can comprise the intensity signal that two photodetectors measure the two bundle orhtogonal linear polarizaiton light returned respectively.
The temperature signal of the fibre optic temperature sensor that the utility model embodiment provides adopts Optical Fiber Transmission, long transmission distance, can reach 400 meters to several kilometers far away; Optical temperature sensing material is as sensing head, and its package dimension is little, site installation test simple and convenient; The demodulator circuit of temperature signal demodulating unit is simple and reliable, can not produce various electromagnetic wave signal to external world, therefore can not disturb other similar components and parts; Further, the operating temperature range of the fibre optic temperature sensor that the utility model provides is wide, between subzero 40 degrees Celsius to 250 degrees Celsius.The fibre optic temperature sensor that these features make the utility model provide refuelling station, storage tank farm can carry out temperature sensing out of doors, and lightning impulse resistant, electromagnetic interference capability are strong, can carry out conduct monitoring at all levels at any time.
The above embodiment only have expressed several embodiment of the present utility model, and it describes comparatively concrete and detailed, but therefore can not be interpreted as the restriction to the utility model the scope of the claims.It should be pointed out that for the person of ordinary skill of the art, without departing from the concept of the premise utility, can also make some distortion and improvement, these all belong to protection domain of the present utility model.Therefore, the protection domain of the utility model patent should be as the criterion with claims.