[1] Hanni J R, Venkata S K. A novel helical electrode type capacitance level sensor for liquid level measurement[J]. Sensors and Actuators A, 315, 112283(2020).

[2] Bera S C, Mandal H, Saha S et al. Study of a modified capacitance-type level transducer for any type of liquid[J]. IEEE Transactions on Instrumentation and Measurement, 63, 641-649(2014).

[3] Sakharov V E, Kuznetsov S A, Zaitsev B D et al. Liquid level sensor using ultrasonic Lamb waves[J]. Ultrasonics, 41, 319-322(2003).

[4] Terzic J, Nagarajah C R, Alamgir M. Fluid level measurement in dynamic environments using a single ultrasonic sensor and Support Vector Machine (SVM)[J]. Sensors and Actuators A, 161, 278-287(2010).

[5] Yan R J, Li H X, Li L Q et al. The design of magnetostrictive liquid level sensor based on DSP[J]. Journal of Taiyuan University of Technology, 39, 289-291(2008).

[6] Yang X H, Huang J, Lu X C et al. Design of intelligent magnetostrictive liquid level gauge[J]. Transducer and Microsystem Technologies, 35, 118-120, 123(2016).

[7] Shao M, Han L, Zhao X et al. Liquid level sensor based on in-fiber Michelson interferometer[J]. Acta Optica Sinica, 38, 0328021(2018).

[8] Bai L, Zheng G, Zhang X X et al. Optical fiber frequency-modulation continuous-wave laser interference liquid level sensor[J]. Laser & Optoelectronics Progress, 58, 0714009(2021).

[9] Ge J F, Cheng X, Gui K et al. Oblique end face coupling optical fiber sensor for point fuel level measurement[J]. Sensors and Actuators A, 297, 111505(2019).

[10] Zhang Y Z, Hou Y L, Zhang Y J et al. Enhancement of a continuous liquid level sensor based on a macro-bend polymer optical fiber coupler[J]. IEEE Photonics Journal, 10, 6800806(2018).

[11] Wang Y, Yan G F, Lian Z G et al. Liquid-level sensing based on a hollow core Bragg fiber[J]. Optics Express, 26, 21656-21663(2018).

[12] Zhao J T, Tong Z R, Yang X F et al. Experimental research of liquid-level sensor using LPFG[J]. Journal of Optoelectronics·Laser, 21, 1777-1779(2010).

[13] Rajamani A S. M D, Sai V V R. Plastic fiber optic sensor for continuous liquid level monitoring[J]. Sensors and Actuators A, 296, 192-199(2019).

[14] Xue P, Bao H Y, Wu B C et al. Fabrication of a screw-shaped plastic optical fiber for liquid level measurement[J]. Optical Fiber Technology, 57, 102237(2020).

[15] Xin X, Wu Y W, Liu H M et al. A new fabrication method of fiber Bragg grating hydrogen sensor[J]. Acta Optica Sinica, 41, 0406002(2021).

[16] Hao J Q, Han B C. Ultrasensitive refractive index sensor based on optical fiber couplers assisted with vernier effect[J]. Acta Optica Sinica, 40, 0206002(2020).

[17] Zhao C R, Ye L, Ge J F et al. Novel light-leaking optical fiber liquid-level sensor for aircraft fuel gauging[J]. Optical Engineering, 52, 014402(2013).

[18] Zhong N B, Li C N, Liu Y et al. Effects of ageing treatment on light transmission and sensitivity of plastic optical fiber sensors[J]. Optics and Precision Engineering, 24, 971-978(2016).

[19] Zhao C R. Research on fiber-optic aircraft fuel level measurement based on light leakage in optical fiber[D]. Wuhan: Huazhong University of Science and Technology(2013).

[20] Zhang H X, Hou Y L, Feng L S et al. Polymer optical fiber continuous liquid level sensor for dynamic measurement[J]. IEEE Sensors Journal, 15, 5238-5242(2015).

[21] Zhong N B, Zhao M F, Liao Q et al. Effect of heat treatments on the performance of polymer optical fiber sensor[J]. Optics Express, 24, 13394-13409(2016).

[22] Chu C S, Lo Y L. A plastic optical fiber sensor for the dual sensing of temperature and oxygen[J]. IEEE Photonics Technology Letters, 20, 63-65(2007).

[23] Zhong N, Liao Q, Zhu X et al. Temperature-independent polymer optical fiber evanescent wave sensor[J]. Scientific Reports, 5, 11508(2015).