CN112729606A - Distributed optical fiber temperature measurement method and system - Google Patents
Distributed optical fiber temperature measurement method and system Download PDFInfo
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Abstract
The invention provides a distributed optical fiber temperature measurement method and a distributed optical fiber temperature measurement system, which solve the problems that the temperature accuracy obtained by the existing Raman signal processing method is poor, and the positioning accuracy of the position of an abnormal temperature point is low. The method comprises the following steps: 1) obtaining an anti-stokes curve and a stokes curve; 2) calculating effective waveforms of a Stokes curve and an anti-Stokes curve; 3) obtaining characteristic waveforms of stokes and anti-stokes; 4) carrying out interpolation operation on the anti-stokes characteristic waveform to obtain the anti-stokes waveform after the scattering phenomenon is eliminated; 5) a ratio mu (N) expression of the anti-Stokes waveform and the Stokes waveform after the scattering phenomenon is eliminated; 6) solving a loss coefficient; 7) a ratio rho (N) expression of the anti-Stokes waveform and the Stokes waveform after the loss coefficient calibration; 8) the measured temperature of the distributed fiber was calculated as follows:
Description
Technical Field
The invention belongs to the field of optical fiber temperature measurement, relates to an optical fiber temperature measurement method, and particularly relates to a distributed optical fiber temperature measurement method and system.
Background
When a light pulse is transmitted along the optical fiber, Raman scattering is generated at every point of the optical fiber, the scattering is emitted in all directions, wherein scattered light transmitted back along the optical fiber becomes backward Raman scattering, and if timing is started when the light enters the optical fiber, the backward scattering light received at different moments represents the distance from the injection end of the optical fiber and the backward Raman scattering occurs, so that the specific position where the scattering occurs can be determined.
The raman scattered light is divided into stokes light and anti-stokes light, wherein the ratio of the intensities of the anti-stokes light and the stokes light is calculated, and the unique temperature can be determined. Temperature measurements at different locations can thus be achieved.
Because the signal-to-noise ratio of the raman signal is low, the existing optical fiber sensor cannot meet the requirements on the aspects of signal detection precision and signal processing capability, and the measured temperature precision is poor due to the influence of factors of light scattering phenomenon and light transmission loss, so that the position of an abnormal temperature point cannot be accurately positioned.
Disclosure of Invention
The invention provides a distributed optical fiber temperature measurement method and a distributed optical fiber temperature measurement system, which aim to solve the technical problem that the position positioning accuracy of an abnormal temperature point is low due to poor temperature accuracy obtained by the existing Raman signal processing method.
In order to achieve the purpose, the technical scheme provided by the invention is as follows:
a distributed optical fiber temperature measurement method is characterized by comprising the following steps:
1) obtaining anti-Stokes and Stokes curves
Pulse light enters the optical fiber through the coupler, Raman scattering occurs in the optical fiber, the generated backward Raman scattering light separates Stokes light from anti-Stokes light through the wavelength division multiplexer, then enters the photoelectric conversion module, and a Stokes curve is obtained through sampling
And anti-stokes curve
Wherein: n is a sample point, N ═ 0,1, 2 … …;
i is the intensity of the Stokes curve, L is the intensity of the anti-Stokes curve;
2) calculating an effective waveform of a Stokes curve and an effective waveform of an anti-Stokes curve
2.1) selecting T sampling points at the tail ends of the Stokes curve and the anti-Stokes curve, and averaging the intensities corresponding to the sampling points to obtain a substrate B of the Stokes curveSAnd base B of the anti-Stokes curveAS(ii) a Wherein T is more than 80 and less than 120;
2.2) according to Stokes curves
And base B of the Stokes curveSThe effective waveform of the stokes curve is obtained as follows:
and according to the anti-Stokes curve of
And base B of the anti-Stokes curveASThe effective waveform of the anti-stokes curve is obtained as follows:
3) characteristic waveforms for obtaining stokes and anti-stokes
Selecting starting point coordinates and end point coordinates of the effective waveform of the Stokes curve and the effective waveform of the anti-Stokes curve; the maximum value of the waveform amplitude of the first half section is obtained to obtain a starting point coordinate; solving the maximum value of the waveform amplitude of the second half section to obtain a terminal point coordinate;
the starting point and the end point of the characteristic waveform of the Stokes curve are respectively (S)m，Im)、(Se，Ie) Then, starting point (S)m，Im) And end point (S)e，Ie) The waveform in between is Stokes characteristic waveform is epsilonS；
The starting point and the end point of the characteristic waveform of the anti-Stokes curve are recorded as((AS)m，Lm)、((AS)e，Le) Then starting point ((AS)m，Lm) And endpoint ((AS)e，Le) The waveform in between is an anti-Stokes characteristic waveform of epsilonAS；
4) Eliminating scattering phenomena by using interpolation algorithm
According to Stokes characteristic waveform epsilonSDetermining the number of sampling points N of a Stokes waveformSAnd e is based on the anti-Stokes characteristic waveformASDetermining the number of anti-stokes waveform sampling points NAS(ii) a For anti-Stokes characteristic waveform epsilonASInterpolation operation is carried out to ensure that the sampling point number of the anti-Stokes characteristic waveform is the same as that of the Stokes waveform, and the anti-Stokes waveform theta after the scattering phenomenon is eliminated is obtainedAS；
5) Obtaining the intensity ratio
Anti-stokes waveform theta after eliminating scattering phenomenonASWith Stokes wave form epsilonSThe ratio μ (N) of:
6) calculating the loss factor
6.1) placing the optical fiber with the head end length of H into a constant temperature bath to obtain mu (0) and mu (H-1); wherein the temperature of the thermostatic bath is F, and H is more than or equal to 100m and less than or equal to 300 m;
6.2) substitution of μ (0) and μ (H-1) into μ (N) in step 5) to determine the loss factor αa-aS；
7) Loss factor calibration
The ratio rho (N) of the anti-Stokes waveform and the Stokes waveform after the loss coefficient calibration is expressed as follows:
8) temperature calibration
The measured temperature of the distributed fiber was calculated as follows:
wherein x is the temperature adjusting temperature difference of the thermostatic bath;
when rho (0) is the temperature F of the thermostatic bath, calculating the ratio of the anti-Stokes waveform to the Stokes waveform according to the formula in the step 7);
ρ' (0) is a ratio of the anti-stokes waveform to the stokes waveform calculated according to the formula in step 7) when the thermostatic bath temperature (F + x) is set.
Further, in step 4), the interpolation operation specifically includes:
a) generating an array with the size of Ns-1: m ═ 1, 2, … Ns-1]；
b) Generating a size of NASThe following groups: x ═ 0, Ns/NAS，2Ns/NAS，...Ns]；
c) Linearly subtracting each value of the array M into an X array;
d) will anti-Stokes characteristic waveform epsilonASConversion to lambdaAS；
e) Will epsilonSIs inserted into λASAnti-stokes waveform theta after eliminating scattering phenomenonAS。
Based on the temperature measurement method, the invention also provides a distributed optical fiber temperature measurement system which is characterized in that: the device comprises a control module, a light source, a coupler, an optical fiber, a wavelength division multiplexer, a photoelectric conversion module, a data acquisition card, a thermostatic bath and a data processing unit;
the control module is used for controlling the synchronous action of the light source and the data acquisition card;
the head end of the optical fiber is arranged in the thermostatic bath;
the coupler is used for coupling pulsed light emitted by the light source into the optical fiber and transmitting Raman scattered light transmitted back through the optical fiber to the wavelength division multiplexer;
the wavelength division multiplexer is used for separating Stokes light and anti-Stokes light of the Raman scattering light and transmitting the Stokes light and the anti-Stokes light to the photoelectric conversion module;
the photoelectric conversion module performs photoelectric conversion on the Stokes light and the anti-Stokes light;
the data acquisition card acquires the Stokes light and the anti-Stokes light converted by the photoelectric conversion module and samples to obtain a Stokes curve and an anti-Stokes curve;
and the data processing unit processes the Stokes curve and the anti-Stokes curve to obtain the thermometer expression measured by the optical fiber.
Compared with the prior art, the invention has the advantages that:
the method of the invention uses a difference value algorithm to eliminate the scattering phenomenon (the number of sampling points of the anti-Stokes curve and the Stokes light is unequal), and is convenient for accurately calculating the intensity ratio of the anti-Stokes curve and the Stokes curve; and the loss coefficient is calibrated by considering the change of the loss coefficient caused by bending, stress, temperature difference and the like. The method provided by the invention can eliminate dispersion and compensate optical fiber loss by interpolation, can effectively eliminate measurement errors, has high demodulation temperature precision and excellent positioning precision, and can accurately position the position of an abnormal temperature point.
Drawings
FIG. 1 is a schematic structural diagram of a distributed optical fiber temperature measurement system according to the present invention;
FIG. 2 is a schematic flow chart of a distributed optical fiber temperature measurement method according to the present invention;
FIG. 3 is a schematic diagram of Stokes and anti-Stokes waveforms in the distributed optical fiber temperature measurement method of the present invention, wherein a is a Stokes curve and b is an anti-Stokes curve;
FIG. 4 is a schematic diagram of starting and ending points of Stokes and anti-Stokes waveforms in the distributed optical fiber temperature measurement method of the present invention, wherein a is a Stokes curve and b is an anti-Stokes curve;
FIG. 5 is a schematic flow chart of the interpolation algorithm in step 4) of the distributed optical fiber temperature measurement method of the present invention;
FIG. 6 is a diagram illustrating the ratio of anti-Stokes to Stokes waveforms in the distributed optical fiber temperature measurement method of the present invention;
FIG. 7 is a diagram illustrating a ratio of anti-Stokes to Stokes waveforms after loss correction in the distributed optical fiber temperature measurement method of the present invention;
wherein the reference numbers are as follows:
1-a control module, 2-a light source, 3-a coupler, 4-an optical fiber, 41-a calibration optical fiber section, 42-a sensing optical fiber section, 5-a thermostatic bath, 6-a wavelength division multiplexer, 7-a photoelectric conversion module, 8-a data acquisition card and 9-a data processing unit.
Detailed Description
The invention is described in further detail below with reference to the figures and specific embodiments.
As shown in fig. 1, a distributed optical fiber temperature measurement system includes a control module 1, a light source 2, a coupler 3, an optical fiber 4, a thermostatic bath 5, a wavelength division multiplexer 6, a photoelectric conversion module 7, a data acquisition card 8 and a data processing unit 9; the control module 1 is used for controlling the synchronous action of the light source 2 and the data acquisition card 8; the optical fiber 4 comprises a calibration optical fiber section 41 and a sensing optical fiber section 42 at the head end, the calibration optical fiber section 41 is arranged in the thermostatic bath 5, and the coupler 3 is used for coupling pulsed light emitted by the light source 2 into the optical fiber 4 and transmitting Raman scattered light transmitted back through the optical fiber 4 to the wavelength division multiplexer 6; the wavelength division multiplexer 6 is used for separating Stokes light and anti-Stokes light of the Raman scattering light and transmitting the separated Stokes light and anti-Stokes light to the photoelectric conversion module 7; the photoelectric conversion module 7 performs photoelectric conversion on both stokes light and anti-stokes light; the data acquisition card 8 acquires the Stokes light and the anti-Stokes light converted by the photoelectric conversion module 7, and samples to obtain a Stokes curve and an anti-Stokes curve; the data processing unit 9 processes the stokes curve and the anti-stokes curve to obtain the temperature measured by the optical fiber 4.
As shown in fig. 2, a distributed optical fiber temperature measurement method includes the following steps:
step one, obtaining an anti-Stokes curve and a Stokes curve
Referring to fig. 1, a control module 1 starts a light source 2 to emit pulsed light, and simultaneously starts a data acquisition card 8 to start working, the pulsed light emitted by the light source 2 enters an optical fiber 4 through a coupler 3, raman scattering occurs at each position in the optical fiber 4, backward raman scattered light is transmitted to a wavelength division multiplexer 6 through the optical fiber 4 and the coupler 3, the raman scattered light at the position is divided into stokes light and anti-stokes light, the stokes light and the anti-stokes light are separated by the wavelength division multiplexer 6, and then enter a photoelectric conversion module 7, and a waveform curve graph of stokes and anti-stokes is obtained by sampling through the data acquisition card 8, as shown in fig. 3;
wherein the curve of Stokes is
And anti-Stokes curve of
N is a sample point, N ═ 0,1, 2, 3 … …; i is the intensity of the stokes curve and L is the intensity of the anti-stokes curve.
The intensity ratio of the anti-stokes curve and the stokes curve satisfies the following formula:
where v is the frequency of the excitation light and v isiIs the vibration frequency, h is the Planck constant, k is the Boltzman constant and T is the absolute temperature, it can be seen from equation (1) that once the laser source 2 used is determined, v is a constant and the material of the fiber 4 determines the molecular vibration frequency viThe ratio of the intensities of the anti-stokes and stokes components uniquely determines the temperature T.
Step two, selecting an effective waveform of a Stokes curve and an effective waveform of an anti-Stokes curve
2.1) selecting T sampling points at the tail ends of the Stokes curve and the anti-Stokes curve, and averaging the intensities corresponding to the sampling points to obtain a substrate B of the Stokes curveSAnd base B of the anti-Stokes curveASWherein T is more than 80 and less than 120; in this embodiment, 100 sampling points T are selected;
2.2) according to Stokes curves
And base B of the Stokes curveSThe effective waveform of the stokes curve is obtained as follows:
according to an anti-Stokes curve of
And base B of the anti-Stokes curveASThe effective waveform of the anti-stokes curve is obtained as follows:
step three, obtaining characteristic waveforms of Stokes and anti-Stokes
Selecting the starting point coordinates and the end point coordinates of the effective waveform of the Stokes curve and the effective waveform of the anti-Stokes curve, as shown in figure 4;
selecting coordinates of a starting point: the maximum value of the waveform amplitude of the first half section is obtained;
selecting a terminal coordinate: the waveform amplitude of the second half section is subjected to maximum value calculation;
the starting point and the end point of the characteristic waveform of the Stokes curve are respectively (S)m，Im)、(Se，Ie) Then, starting point (S)m，Im) And end point (S)e，Ie) The waveform in between is Stokes characteristic waveform is epsilonS；
The starting point and the end point of the characteristic waveform of the anti-Stokes curve are recorded AS (AS)m，Lm)、((AS)e，Le) Then starting point ((AS)m，Lm) And endpoint ((AS)e，Le) The waveform in between is an anti-Stokes characteristic waveform of epsilonAS；
Step four, eliminating scattering phenomenon by using interpolation algorithm
According to Stokes characteristic waveform epsilonSDetermining the number of sampling points N of a Stokes waveformSAnd e is based on the anti-Stokes characteristic waveformASDetermining the number of anti-stokes waveform sampling points NAS(ii) a Because the light speeds of the Stokes light and the anti-Stokes light in the optical fiber 4 are different, the sampling machine at the same time acquires two light signals corresponding to different scattering point positions, which is specifically reflected in NSAnd NASNot equal, therefore, the present embodiment applies an interpolation algorithm to eliminate the scattering phenomenon, i.e., for the anti-stokes characteristic waveform εASInterpolation operation is carried out to ensure that the sampling point number of the anti-Stokes characteristic waveform is the same as that of the Stokes waveform, and the anti-Stokes waveform theta after the scattering phenomenon is eliminated is obtainedAS(ii) a The flowchart of the interpolation operation is shown in fig. 5, and specifically as follows:
a) generate an array of size NS-1:
M＝[1，2，…Ns-1] (4)
b) generating a size of NASArray of
X＝[0，Ns/NAS，2Ns/NAS，...Ns] (5)
c) Linearly subtracting each value of the array M into an X array;
d) will anti-Stokes characteristic waveform epsilonASConversion to lambdaAS；
e) Will epsilonSIs inserted into λASAnti-stokes waveform theta after eliminating scattering phenomenonAS。
Step five, obtaining the strength ratio
Anti-stokes waveform thetaASWith Stokes wave form epsilonSRatios were made as shown in fig. 6:
the ratio mu (N) and the temperature T (N) are in a linear relation;
the loss coefficients of the stokes optical signal and the anti-stokes optical signal are very small in difference, when the external environment changes, the loss coefficients can be changed due to the bending, stress and temperature difference, the two are generally considered to be equal or fixed and are ignored in correcting the difference, and therefore the method of the embodiment corrects the difference
Performing compensation;
the stokes signature can be expressed as:
the anti-stokes signature can be expressed as:
the ratio μ (N) of the stokes signature to the anti-stokes signature is expressed as:
when N is equal to 0, the compound is,
then
Step six, solving the loss coefficient
The optical fiber 4 with the head end length of H (H is more than or equal to 100m and less than or equal to 300m) is placed in a constant temperature tank 5 (the temperature of the constant temperature tank 5 is F), and mu (0) can be obtained) Mu (H-1); in this embodiment, when 200m is used as H, μ (0) and μ (199) can be obtained by placing the optical fiber 4 having a head end length of 200m in the thermostat 5 having a temperature of F, and μ (0) and μ (199) are substituted into the above equation (11), so that the loss coefficient α can be obtaineda-aS；
Step seven, calibrating the loss coefficient
As shown in fig. 7, the ratio of the anti-stokes waveform to the stokes waveform after the loss factor calibration is:
step eight, temperature calibration
Adjusting the temperature of the thermostatic bath 5 to (F + x) ° c, wherein x is the temperature adjustment temperature difference of the thermostatic bath 5, calculating the position where N is 0 according to formula (12), wherein the stokes ratio and the anti-stokes ratio is ρ '(0), and obtaining a relational expression of the anti-stokes/stokes ratio ρ (N) and the temperature t (N) according to ρ (0), ρ' (0), F and (F + x):
wherein ρ (0) is a ρ (0) value calculated according to the formula (12) when the temperature of the thermostatic bath 5 is F, and ρ '(0) is a ρ' (0) value calculated according to the formula (12) when the temperature of the thermostatic bath 5 is (F + x);
assuming that the temperature of the thermostatic bath 5 is adjusted to (F +10) ° c in this embodiment, the temperature t (n) is:
because the light speeds of stokes and anti-stokes in the optical fiber 4 are different, the number of sampling points of stokes waveforms and the number of sampling points of anti-stokes waveforms at the same moment are unequal, the method of the embodiment eliminates the scattering phenomenon (the number of sampling points of two paths of light is unequal) by using an interpolation algorithm, and is convenient for calculating the intensity ratio of an anti-stokes curve and a stokes curve. The method of the embodiment also compensates the intensity ratio of the anti-Stokes curve and the Stokes curve, can effectively eliminate measurement errors, and has high demodulation temperature precision and excellent positioning precision.
The above description is only for the purpose of describing the preferred embodiments of the present invention and does not limit the technical solutions of the present invention, and any known modifications made by those skilled in the art based on the main technical concepts of the present invention fall within the technical scope of the present invention.
Claims (3)
1. A distributed optical fiber temperature measurement method is characterized by comprising the following steps:
1) obtaining anti-Stokes and Stokes curves
Pulse light enters an optical fiber (4) through a coupler (3), Raman scattering occurs in the optical fiber (4), generated backward Raman scattering light separates Stokes light from anti-Stokes light through a wavelength division multiplexer (6), then enters a photoelectric conversion module (7), and a Stokes curve is obtained through sampling
And anti-stokes curve
Wherein: n is a sample point, N ═ 0,1, 2 … …;
i is the intensity of the Stokes curve, L is the intensity of the anti-Stokes curve;
2) calculating an effective waveform of a Stokes curve and an effective waveform of an anti-Stokes curve
2.1) selecting T sampling points at the tail ends of the Stokes curve and the anti-Stokes curve, and averaging the intensities corresponding to the sampling points to obtain a substrate B of the Stokes curveSAnd base B of the anti-Stokes curveAS(ii) a Wherein T is more than 80 and less than 120;
2.2) according to Stokes curves
And base B of the Stokes curveSThe effective waveform of the stokes curve is obtained as follows:
and according to the anti-Stokes curve of
And base B of the anti-Stokes curveASThe effective waveform of the anti-stokes curve is obtained as follows:
3) characteristic waveforms for obtaining stokes and anti-stokes
Selecting starting point coordinates and end point coordinates of the effective waveform of the Stokes curve and the effective waveform of the anti-Stokes curve; the maximum value of the waveform amplitude of the first half section is obtained to obtain a starting point coordinate; solving the maximum value of the waveform amplitude of the second half section to obtain a terminal point coordinate;
the starting point and the end point of the characteristic waveform of the Stokes curve are respectively (S)m，Im)、(Se，Ie) Then, starting point (S)m，Im) And end point (S)e，Ie) The waveform in between is Stokes characteristic waveform is epsilonS；
The starting point and the end point of the characteristic waveform of the anti-Stokes curve are recorded AS (AS)m，Lm)、((AS)e，Le) Then starting point ((AS)m，Lm) And endpoint ((AS)e，Le) The waveform in between is an anti-Stokes characteristic waveform of epsilonAS；
4) Eliminating scattering phenomena by using interpolation algorithm
According to Stokes characteristic waveform epsilonSDetermining the number of sampling points N of a Stokes waveformSAnd e is based on the anti-Stokes characteristic waveformASDetermining the number of anti-stokes waveform sampling points NAS(ii) a For anti-StokesCharacteristic waveform epsilonASInterpolation operation is carried out to ensure that the sampling point number of the anti-Stokes characteristic waveform is the same as that of the Stokes waveform, and the anti-Stokes waveform theta after the scattering phenomenon is eliminated is obtainedAS；
5) Obtaining the intensity ratio
Anti-stokes waveform theta after eliminating scattering phenomenonASWith Stokes wave form epsilonSThe ratio μ (N) of:
6) calculating the loss factor
6.1) placing the optical fiber (4) with the head end length of H into a constant temperature groove (5) to obtain mu (0) and mu (H-1); wherein the temperature of the constant temperature groove (5) is F, and H is more than or equal to 100m and less than or equal to 300 m;
6.2) substitution of μ (0) and μ (H-1) into μ (N) in step 5) to determine the loss factor αa-as；
7) Loss factor calibration
The ratio rho (N) of the anti-Stokes waveform and the Stokes waveform after the loss coefficient calibration is expressed as follows:
8) temperature calibration
The measured temperature of the distributed fiber was calculated as follows:
wherein x is the temperature adjusting temperature difference of the thermostatic bath (5);
rho (0) is the ratio of the anti-stokes waveform to the stokes waveform calculated according to the formula in the step 7) when the temperature F of the thermostatic bath (5) is reached;
ρ' (0) is a ratio of the anti-stokes waveform to the stokes waveform calculated according to the formula in step 7) when the temperature (F + x) of the thermostatic bath (5) is zero.
2. The distributed optical fiber temperature measurement method according to claim 1, wherein in step 4), the interpolation operation is specifically as follows:
a) generating an array with the size of Ns-1: m ═ 1, 2, … Ns-1]；
b) Generating a size of NASThe following groups: x ═ 0, Ns/NAS，2Ns/NAS，...Ns]；
c) Linearly subtracting each value of the array M into an X array;
d) will anti-Stokes characteristic waveform epsilonASConversion to lambdaAS；
e) Will epsilonSIs inserted into λASAnti-stokes waveform theta after eliminating scattering phenomenonAS。
3. A distributed optical fiber temperature measurement system for implementing the distributed optical fiber temperature measurement method according to claim 1, characterized in that: the device comprises a control module (1), a light source (2), a coupler (3), an optical fiber (4), a wavelength division multiplexer (6), a photoelectric conversion module (7), a data acquisition card (8), a thermostatic bath (5) and a data processing unit (9);
the control module (1) is used for controlling the synchronous action of the light source (2) and the data acquisition card (8);
the head end of the optical fiber (4) is arranged in the thermostatic bath (5);
the coupler (3) is used for coupling pulsed light emitted by the light source (2) into the optical fiber (4) and transmitting Raman scattering light transmitted back through the optical fiber (4) to the wavelength division multiplexer (6);
the wavelength division multiplexer (6) is used for separating Stokes light and anti-Stokes light of Raman scattering light and transmitting the Stokes light and the anti-Stokes light to the photoelectric conversion module (7);
the photoelectric conversion module (7) performs photoelectric conversion on the Stokes light and the anti-Stokes light;
the data acquisition card (8) acquires the Stokes light and the anti-Stokes light converted by the photoelectric conversion module (7), and samples to obtain a Stokes curve and an anti-Stokes curve;
and the data processing unit (9) processes the Stokes curve and the anti-Stokes curve to obtain a temperature expression measured by the optical fiber (4).
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| MANOJ KUMAR SAXENA等: "Empirical Mode Decomposition-Based Detection of Bend-Induced Error and Its Correction in a Raman Optical Fiber Distributed Temperature Sensor", 《IEEE SENSORS JOURNAL》 * |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114577367A (en) * | 2022-05-06 | 2022-06-03 | 苏州光格科技股份有限公司 | Optical fiber temperature sensor calibration method and device and computer equipment |
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