Abstract

This article presents a miniature, high-sensitivity, all-silica Fabry–Perot fiber-optic sensor suitable for simultaneous measurements of pressure and temperature. The proposed sensor diameter does not exceed 125 μm and consists of two low-finesse Fabry–Perot resonators created at the tip of an optical fiber. The first resonator is embodied in the form of a short air cavity positioned at the tip of the fiber. This resonator utilizes a thin silica diaphragm to achieve the sensor’s pressure response. The second resonator exploits the refractive index dependence of silica fiber in order to provide the proposed sensor’s temperature measurement function. Both resonators have substantially different lengths that permit straightforward spectrally resolved signal processing and unambiguous determination of the applied pressure and temperature.

© 2012 Optical Society of America

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References

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  1. G. Z. Wang, A. B. Wang, K. A. Murphy, and A. M. Vengsarkar, “Two-mode Fabry-Perot optical fibre sensors for strain and temperature,” Electron. Lett. 27, 1843–1845 (1991).
    [CrossRef]
  2. Y. G. Han, S. Song, G. H. Kim, K. Lee, S. B. Lee, J. H. Lee, C. H. Jeong, C. H. Oh, and H. J. Kang, “Simultaneous independent measurement of strain and temperature based on long-period fiber gratings inscribed in holey fibers depending on air-hole size,” Opt. Lett. 32, 2245–2247 (2007).
    [CrossRef]
  3. Y. J. Rao, Z. L. Ran, X. Liao, and H. Y. Deng, “Hybrid LPFG/MEFPI sensor for simultaneous measurement of high-temperature and strain,” Opt. Express 15, 14936–14941 (2007).
    [CrossRef]
  4. J. Xu, Y.-g. Liu, Z. Wang, and B. Tai, “Simultaneous force and temperature measurement using long-period grating written on the joint of a microstructured optical fiber and a single mode fiber,” Appl. Opt. 49, 492–496 (2010).
    [CrossRef]
  5. B. Dong, J. Hao, C. Liaw, B. Lin, and S. C. Tjin, “Simultaneous strain and temperature measurement using a compact photonic crystal fiber inter-modal interferometer and a fiber Bragg grating,” Appl. Opt. 49, 6232–6235 (2010).
    [CrossRef]
  6. H. Y. Choi, G. Mudhana, K. S. Park, U. C. Paek, and B. H. Lee, “Cross-talk free and ultra-compact fiber optic sensor for simultaneous measurement of temperature and refractive index,” Opt. Express 18, 141–149 (2010).
    [CrossRef]
  7. A. P. Zhang, L. Y. Shao, J. F. Ding, and S. He, “Sandwiched long-period gratings for simultaneous measurement of refractive index and temperature,” IEEE Photon. Technol. Lett. 17, 2397–2399 (2005).
    [CrossRef]
  8. D. W. Kim, F. Shen, X. Chen, and A. Wang, “Simultaneous measurement of refractive index and temperature based on a reflection-mode long-period grating and an intrinsic Fabry–Perot interferometer sensor,” Opt. Lett. 30, 3000–3002 (2005).
    [CrossRef]
  9. Y. J. Rao, M. Deng, D. W. Duan, and T. Zhu, “In-line fiber Fabry–Perot refractive-index tip sensor based on endlessly photonic crystal fiber,” Sens. Actuators A 148, 33–38 (2008).
    [CrossRef]
  10. L. A. Ferreira, A. B. L. Ribeiro, J. L. Santos, and F. Farahi, “Simultaneous measurement of displacement and temperature using a low finesse cavity and a fiber Bragg grating,” IEEE Photon. Technol. Lett. 8, 1519–1521 (1996).
    [CrossRef]
  11. C.-W. Lai, Y.-L. Lo, J.-P. Yur, W.-F. Liu, and C.-H. Chuang, “Application of Fabry-Pérot and fiber Bragg grating pressure sensors to simultaneous measurement of liquid level and specific gravity,” Measurement 45, 469–473 (2012).
    [CrossRef]
  12. Y. Liu, Z. Guo, Y. Zhang, K. S. Chiang, and X. Dong, “Simultaneous pressure and temperature measurement with polymer-coated fibre Bragg grating,” Electron. Lett. 36, 564–566 (2000).
    [CrossRef]
  13. T. Guo, X. Qiao, Z. Jia, Q. Zhao, and X. Dong, “Simultaneous measurement of temperature and pressure by a single fiber Bragg grating with a broadened reflection spectrum,” Appl. Opt. 45, 2935–2939 (2006).
    [CrossRef]
  14. K. Bremer, E. Lewis, G. Leen, and B. Moss, “Fibre optic pressure and temperature sensor for geothermal wells,” in Proceedings of IEEE Sensors 2010 Conference (IEEE, 2010), pp. 538–541.
  15. K. Bremer, E. Lewis, G. Leen, B. Moss, S. Lochmann, and I. A. R. Mueller, “Feedback stabilized interrogation technique for EFPI/FBG hybrid fiber-optic pressure and temperature sensors,” IEEE Sens. J. 12, 133–138 (2012).
    [CrossRef]
  16. J. A. Etches and G. F. Fernando, “Evaluation of embedded optical fiber sensors in composites: EFPI sensor fabrication and quasi-static evaluation,” Polym. Compos. 30, 1265–1274 (2009).
    [CrossRef]
  17. E. Cibula and D. Đonlagić, “Low-loss semi-reflective in-fiber mirrors,“ Opt. Express 18, 12017–12026 (2010).
    [CrossRef]
  18. E. Cibula and D. Đonlagić, “Miniature fiber-optic pressure sensor with a polymer diaphragm,” Appl. Opt. 44, 2736–2744 (2005).
    [CrossRef]
  19. E. Cibula, S. Pevec, B. Lenardič, E. Pinet, and D. Đonlagić, “Miniature all-glass robust pressure sensor,“ Opt. Express 17, 5098–5106 (2009).
    [CrossRef]
  20. D. Đonlagić and E. Cibula, “All-fiber high-sensitivity pressure sensor with SiO2 diaphragm,” Opt. Lett. 30, 2071–2073 (2005).
    [CrossRef]

2012 (2)

C.-W. Lai, Y.-L. Lo, J.-P. Yur, W.-F. Liu, and C.-H. Chuang, “Application of Fabry-Pérot and fiber Bragg grating pressure sensors to simultaneous measurement of liquid level and specific gravity,” Measurement 45, 469–473 (2012).
[CrossRef]

K. Bremer, E. Lewis, G. Leen, B. Moss, S. Lochmann, and I. A. R. Mueller, “Feedback stabilized interrogation technique for EFPI/FBG hybrid fiber-optic pressure and temperature sensors,” IEEE Sens. J. 12, 133–138 (2012).
[CrossRef]

2010 (4)

2009 (2)

J. A. Etches and G. F. Fernando, “Evaluation of embedded optical fiber sensors in composites: EFPI sensor fabrication and quasi-static evaluation,” Polym. Compos. 30, 1265–1274 (2009).
[CrossRef]

E. Cibula, S. Pevec, B. Lenardič, E. Pinet, and D. Đonlagić, “Miniature all-glass robust pressure sensor,“ Opt. Express 17, 5098–5106 (2009).
[CrossRef]

2008 (1)

Y. J. Rao, M. Deng, D. W. Duan, and T. Zhu, “In-line fiber Fabry–Perot refractive-index tip sensor based on endlessly photonic crystal fiber,” Sens. Actuators A 148, 33–38 (2008).
[CrossRef]

2007 (2)

2006 (1)

2005 (4)

2000 (1)

Y. Liu, Z. Guo, Y. Zhang, K. S. Chiang, and X. Dong, “Simultaneous pressure and temperature measurement with polymer-coated fibre Bragg grating,” Electron. Lett. 36, 564–566 (2000).
[CrossRef]

1996 (1)

L. A. Ferreira, A. B. L. Ribeiro, J. L. Santos, and F. Farahi, “Simultaneous measurement of displacement and temperature using a low finesse cavity and a fiber Bragg grating,” IEEE Photon. Technol. Lett. 8, 1519–1521 (1996).
[CrossRef]

1991 (1)

G. Z. Wang, A. B. Wang, K. A. Murphy, and A. M. Vengsarkar, “Two-mode Fabry-Perot optical fibre sensors for strain and temperature,” Electron. Lett. 27, 1843–1845 (1991).
[CrossRef]

Bremer, K.

K. Bremer, E. Lewis, G. Leen, B. Moss, S. Lochmann, and I. A. R. Mueller, “Feedback stabilized interrogation technique for EFPI/FBG hybrid fiber-optic pressure and temperature sensors,” IEEE Sens. J. 12, 133–138 (2012).
[CrossRef]

K. Bremer, E. Lewis, G. Leen, and B. Moss, “Fibre optic pressure and temperature sensor for geothermal wells,” in Proceedings of IEEE Sensors 2010 Conference (IEEE, 2010), pp. 538–541.

Chen, X.

Chiang, K. S.

Y. Liu, Z. Guo, Y. Zhang, K. S. Chiang, and X. Dong, “Simultaneous pressure and temperature measurement with polymer-coated fibre Bragg grating,” Electron. Lett. 36, 564–566 (2000).
[CrossRef]

Choi, H. Y.

Chuang, C.-H.

C.-W. Lai, Y.-L. Lo, J.-P. Yur, W.-F. Liu, and C.-H. Chuang, “Application of Fabry-Pérot and fiber Bragg grating pressure sensors to simultaneous measurement of liquid level and specific gravity,” Measurement 45, 469–473 (2012).
[CrossRef]

Cibula, E.

Deng, H. Y.

Deng, M.

Y. J. Rao, M. Deng, D. W. Duan, and T. Zhu, “In-line fiber Fabry–Perot refractive-index tip sensor based on endlessly photonic crystal fiber,” Sens. Actuators A 148, 33–38 (2008).
[CrossRef]

Ding, J. F.

A. P. Zhang, L. Y. Shao, J. F. Ding, and S. He, “Sandwiched long-period gratings for simultaneous measurement of refractive index and temperature,” IEEE Photon. Technol. Lett. 17, 2397–2399 (2005).
[CrossRef]

Dong, B.

Dong, X.

T. Guo, X. Qiao, Z. Jia, Q. Zhao, and X. Dong, “Simultaneous measurement of temperature and pressure by a single fiber Bragg grating with a broadened reflection spectrum,” Appl. Opt. 45, 2935–2939 (2006).
[CrossRef]

Y. Liu, Z. Guo, Y. Zhang, K. S. Chiang, and X. Dong, “Simultaneous pressure and temperature measurement with polymer-coated fibre Bragg grating,” Electron. Lett. 36, 564–566 (2000).
[CrossRef]

Ðonlagic, D.

Duan, D. W.

Y. J. Rao, M. Deng, D. W. Duan, and T. Zhu, “In-line fiber Fabry–Perot refractive-index tip sensor based on endlessly photonic crystal fiber,” Sens. Actuators A 148, 33–38 (2008).
[CrossRef]

Etches, J. A.

J. A. Etches and G. F. Fernando, “Evaluation of embedded optical fiber sensors in composites: EFPI sensor fabrication and quasi-static evaluation,” Polym. Compos. 30, 1265–1274 (2009).
[CrossRef]

Farahi, F.

L. A. Ferreira, A. B. L. Ribeiro, J. L. Santos, and F. Farahi, “Simultaneous measurement of displacement and temperature using a low finesse cavity and a fiber Bragg grating,” IEEE Photon. Technol. Lett. 8, 1519–1521 (1996).
[CrossRef]

Fernando, G. F.

J. A. Etches and G. F. Fernando, “Evaluation of embedded optical fiber sensors in composites: EFPI sensor fabrication and quasi-static evaluation,” Polym. Compos. 30, 1265–1274 (2009).
[CrossRef]

Ferreira, L. A.

L. A. Ferreira, A. B. L. Ribeiro, J. L. Santos, and F. Farahi, “Simultaneous measurement of displacement and temperature using a low finesse cavity and a fiber Bragg grating,” IEEE Photon. Technol. Lett. 8, 1519–1521 (1996).
[CrossRef]

Guo, T.

Guo, Z.

Y. Liu, Z. Guo, Y. Zhang, K. S. Chiang, and X. Dong, “Simultaneous pressure and temperature measurement with polymer-coated fibre Bragg grating,” Electron. Lett. 36, 564–566 (2000).
[CrossRef]

Han, Y. G.

Hao, J.

He, S.

A. P. Zhang, L. Y. Shao, J. F. Ding, and S. He, “Sandwiched long-period gratings for simultaneous measurement of refractive index and temperature,” IEEE Photon. Technol. Lett. 17, 2397–2399 (2005).
[CrossRef]

Jeong, C. H.

Jia, Z.

Kang, H. J.

Kim, D. W.

Kim, G. H.

Lai, C.-W.

C.-W. Lai, Y.-L. Lo, J.-P. Yur, W.-F. Liu, and C.-H. Chuang, “Application of Fabry-Pérot and fiber Bragg grating pressure sensors to simultaneous measurement of liquid level and specific gravity,” Measurement 45, 469–473 (2012).
[CrossRef]

Lee, B. H.

Lee, J. H.

Lee, K.

Lee, S. B.

Leen, G.

K. Bremer, E. Lewis, G. Leen, B. Moss, S. Lochmann, and I. A. R. Mueller, “Feedback stabilized interrogation technique for EFPI/FBG hybrid fiber-optic pressure and temperature sensors,” IEEE Sens. J. 12, 133–138 (2012).
[CrossRef]

K. Bremer, E. Lewis, G. Leen, and B. Moss, “Fibre optic pressure and temperature sensor for geothermal wells,” in Proceedings of IEEE Sensors 2010 Conference (IEEE, 2010), pp. 538–541.

Lenardic, B.

Lewis, E.

K. Bremer, E. Lewis, G. Leen, B. Moss, S. Lochmann, and I. A. R. Mueller, “Feedback stabilized interrogation technique for EFPI/FBG hybrid fiber-optic pressure and temperature sensors,” IEEE Sens. J. 12, 133–138 (2012).
[CrossRef]

K. Bremer, E. Lewis, G. Leen, and B. Moss, “Fibre optic pressure and temperature sensor for geothermal wells,” in Proceedings of IEEE Sensors 2010 Conference (IEEE, 2010), pp. 538–541.

Liao, X.

Liaw, C.

Lin, B.

Liu, W.-F.

C.-W. Lai, Y.-L. Lo, J.-P. Yur, W.-F. Liu, and C.-H. Chuang, “Application of Fabry-Pérot and fiber Bragg grating pressure sensors to simultaneous measurement of liquid level and specific gravity,” Measurement 45, 469–473 (2012).
[CrossRef]

Liu, Y.

Y. Liu, Z. Guo, Y. Zhang, K. S. Chiang, and X. Dong, “Simultaneous pressure and temperature measurement with polymer-coated fibre Bragg grating,” Electron. Lett. 36, 564–566 (2000).
[CrossRef]

Liu, Y.-g.

Lo, Y.-L.

C.-W. Lai, Y.-L. Lo, J.-P. Yur, W.-F. Liu, and C.-H. Chuang, “Application of Fabry-Pérot and fiber Bragg grating pressure sensors to simultaneous measurement of liquid level and specific gravity,” Measurement 45, 469–473 (2012).
[CrossRef]

Lochmann, S.

K. Bremer, E. Lewis, G. Leen, B. Moss, S. Lochmann, and I. A. R. Mueller, “Feedback stabilized interrogation technique for EFPI/FBG hybrid fiber-optic pressure and temperature sensors,” IEEE Sens. J. 12, 133–138 (2012).
[CrossRef]

Moss, B.

K. Bremer, E. Lewis, G. Leen, B. Moss, S. Lochmann, and I. A. R. Mueller, “Feedback stabilized interrogation technique for EFPI/FBG hybrid fiber-optic pressure and temperature sensors,” IEEE Sens. J. 12, 133–138 (2012).
[CrossRef]

K. Bremer, E. Lewis, G. Leen, and B. Moss, “Fibre optic pressure and temperature sensor for geothermal wells,” in Proceedings of IEEE Sensors 2010 Conference (IEEE, 2010), pp. 538–541.

Mudhana, G.

Mueller, I. A. R.

K. Bremer, E. Lewis, G. Leen, B. Moss, S. Lochmann, and I. A. R. Mueller, “Feedback stabilized interrogation technique for EFPI/FBG hybrid fiber-optic pressure and temperature sensors,” IEEE Sens. J. 12, 133–138 (2012).
[CrossRef]

Murphy, K. A.

G. Z. Wang, A. B. Wang, K. A. Murphy, and A. M. Vengsarkar, “Two-mode Fabry-Perot optical fibre sensors for strain and temperature,” Electron. Lett. 27, 1843–1845 (1991).
[CrossRef]

Oh, C. H.

Paek, U. C.

Park, K. S.

Pevec, S.

Pinet, E.

Qiao, X.

Ran, Z. L.

Rao, Y. J.

Y. J. Rao, M. Deng, D. W. Duan, and T. Zhu, “In-line fiber Fabry–Perot refractive-index tip sensor based on endlessly photonic crystal fiber,” Sens. Actuators A 148, 33–38 (2008).
[CrossRef]

Y. J. Rao, Z. L. Ran, X. Liao, and H. Y. Deng, “Hybrid LPFG/MEFPI sensor for simultaneous measurement of high-temperature and strain,” Opt. Express 15, 14936–14941 (2007).
[CrossRef]

Ribeiro, A. B. L.

L. A. Ferreira, A. B. L. Ribeiro, J. L. Santos, and F. Farahi, “Simultaneous measurement of displacement and temperature using a low finesse cavity and a fiber Bragg grating,” IEEE Photon. Technol. Lett. 8, 1519–1521 (1996).
[CrossRef]

Santos, J. L.

L. A. Ferreira, A. B. L. Ribeiro, J. L. Santos, and F. Farahi, “Simultaneous measurement of displacement and temperature using a low finesse cavity and a fiber Bragg grating,” IEEE Photon. Technol. Lett. 8, 1519–1521 (1996).
[CrossRef]

Shao, L. Y.

A. P. Zhang, L. Y. Shao, J. F. Ding, and S. He, “Sandwiched long-period gratings for simultaneous measurement of refractive index and temperature,” IEEE Photon. Technol. Lett. 17, 2397–2399 (2005).
[CrossRef]

Shen, F.

Song, S.

Tai, B.

Tjin, S. C.

Vengsarkar, A. M.

G. Z. Wang, A. B. Wang, K. A. Murphy, and A. M. Vengsarkar, “Two-mode Fabry-Perot optical fibre sensors for strain and temperature,” Electron. Lett. 27, 1843–1845 (1991).
[CrossRef]

Wang, A.

Wang, A. B.

G. Z. Wang, A. B. Wang, K. A. Murphy, and A. M. Vengsarkar, “Two-mode Fabry-Perot optical fibre sensors for strain and temperature,” Electron. Lett. 27, 1843–1845 (1991).
[CrossRef]

Wang, G. Z.

G. Z. Wang, A. B. Wang, K. A. Murphy, and A. M. Vengsarkar, “Two-mode Fabry-Perot optical fibre sensors for strain and temperature,” Electron. Lett. 27, 1843–1845 (1991).
[CrossRef]

Wang, Z.

Xu, J.

Yur, J.-P.

C.-W. Lai, Y.-L. Lo, J.-P. Yur, W.-F. Liu, and C.-H. Chuang, “Application of Fabry-Pérot and fiber Bragg grating pressure sensors to simultaneous measurement of liquid level and specific gravity,” Measurement 45, 469–473 (2012).
[CrossRef]

Zhang, A. P.

A. P. Zhang, L. Y. Shao, J. F. Ding, and S. He, “Sandwiched long-period gratings for simultaneous measurement of refractive index and temperature,” IEEE Photon. Technol. Lett. 17, 2397–2399 (2005).
[CrossRef]

Zhang, Y.

Y. Liu, Z. Guo, Y. Zhang, K. S. Chiang, and X. Dong, “Simultaneous pressure and temperature measurement with polymer-coated fibre Bragg grating,” Electron. Lett. 36, 564–566 (2000).
[CrossRef]

Zhao, Q.

Zhu, T.

Y. J. Rao, M. Deng, D. W. Duan, and T. Zhu, “In-line fiber Fabry–Perot refractive-index tip sensor based on endlessly photonic crystal fiber,” Sens. Actuators A 148, 33–38 (2008).
[CrossRef]

Appl. Opt. (4)

Electron. Lett. (2)

G. Z. Wang, A. B. Wang, K. A. Murphy, and A. M. Vengsarkar, “Two-mode Fabry-Perot optical fibre sensors for strain and temperature,” Electron. Lett. 27, 1843–1845 (1991).
[CrossRef]

Y. Liu, Z. Guo, Y. Zhang, K. S. Chiang, and X. Dong, “Simultaneous pressure and temperature measurement with polymer-coated fibre Bragg grating,” Electron. Lett. 36, 564–566 (2000).
[CrossRef]

IEEE Photon. Technol. Lett. (2)

L. A. Ferreira, A. B. L. Ribeiro, J. L. Santos, and F. Farahi, “Simultaneous measurement of displacement and temperature using a low finesse cavity and a fiber Bragg grating,” IEEE Photon. Technol. Lett. 8, 1519–1521 (1996).
[CrossRef]

A. P. Zhang, L. Y. Shao, J. F. Ding, and S. He, “Sandwiched long-period gratings for simultaneous measurement of refractive index and temperature,” IEEE Photon. Technol. Lett. 17, 2397–2399 (2005).
[CrossRef]

IEEE Sens. J. (1)

K. Bremer, E. Lewis, G. Leen, B. Moss, S. Lochmann, and I. A. R. Mueller, “Feedback stabilized interrogation technique for EFPI/FBG hybrid fiber-optic pressure and temperature sensors,” IEEE Sens. J. 12, 133–138 (2012).
[CrossRef]

Measurement (1)

C.-W. Lai, Y.-L. Lo, J.-P. Yur, W.-F. Liu, and C.-H. Chuang, “Application of Fabry-Pérot and fiber Bragg grating pressure sensors to simultaneous measurement of liquid level and specific gravity,” Measurement 45, 469–473 (2012).
[CrossRef]

Opt. Express (4)

Opt. Lett. (3)

Polym. Compos. (1)

J. A. Etches and G. F. Fernando, “Evaluation of embedded optical fiber sensors in composites: EFPI sensor fabrication and quasi-static evaluation,” Polym. Compos. 30, 1265–1274 (2009).
[CrossRef]

Sens. Actuators A (1)

Y. J. Rao, M. Deng, D. W. Duan, and T. Zhu, “In-line fiber Fabry–Perot refractive-index tip sensor based on endlessly photonic crystal fiber,” Sens. Actuators A 148, 33–38 (2008).
[CrossRef]

Other (1)

K. Bremer, E. Lewis, G. Leen, and B. Moss, “Fibre optic pressure and temperature sensor for geothermal wells,” in Proceedings of IEEE Sensors 2010 Conference (IEEE, 2010), pp. 538–541.

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Figures (7)

Fig. 1.
Fig. 1.

Scheme of FP interferometer.

Fig. 2.
Fig. 2.

Micromachining of proposed sensor: (a) etching of SMF and SFF for time t1 and t2 (this process is performed in batches), (b) in-line mirror creation by fusion splicing, (c) cleaving, (d) fusion splicing of etched SFF to SMF end surface, (e) precision cleaving near splice, (f) polishing, (g) final etching (sensitivity tuning).

Fig. 3.
Fig. 3.

Experimental setup for temperature–pressure measurement.

Fig. 4.
Fig. 4.

Output spectral characteristic of temperature–pressure sensor.

Fig. 5.
Fig. 5.

Wavelength shift of selected peak within high-frequency spectral fringe due to pressure change at two different temperatures.

Fig. 6.
Fig. 6.

Temperature measurement at different pressures: (a) expected temperature–pressure dependence, (b) compensated measurement.

Fig. 7.
Fig. 7.

Pressure measurements at different temperatures.

Equations (9)

Equations on this page are rendered with MathJax. Learn more.

IR=A+Bcos(Φ1)low frequency component+Ccos(Φ2)+Dcos(Φ1+Φ2)high frequency components,A=R3+(1α3)2(1R3)2(R2+(1α2)2(1R2)2R1),B=2R3R2(1α3)(1R3),C=2R2R1(1α3)2(1α2)(1R3)2(1R2),D=2R3R1(1α3)(1α2)(1R3)(1R2),
Φ1=4πn2L2λ,Φ2=4πn1L1λ+π.
Δλ=λdndTΔTn=kTΔT.
ΔTmax=FSRkTλ=λ22nL1kT.
Δλ=λkPL1Δp=kpsΔp,
Δpmax=λ2kp,
p=pcal+(λcal_pλmeasured_LF)1kps,
T=Tcal+(λmeasured_HFλcal_T+kPTp)1kT,
kPT=Δλcal_TΔpcal_T.

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