Polymer Optical Fiber Intensity-Based Sensor for Liquid-Level Measurements in Volumetric Flasks for Industrial Application

Table 2

Performance of the different liquid level detection POF intensity-based optical sensors.

	ZED 1		ZED 2		ZED 3
	Sensor 1^a	Sensor 2^b	Sensor 1^c	Sensor 2^d	Sensor 1^e	Sensor 2^f
Linearity	—	0.9877	—	0.9777	0.9649	—
Sensitivity	5.3% F.S.	1.3 dB/discrete level	12% F.S.	0.35 dB/discrete level	0.85 dB/discrete level	1.7% F.S.
Measurements standard deviation	<9%	<8%	<5%	<5%	<12%	<2%

Linearity is given in terms of the linear regression coefficient; F.S.: full-scale.
^aAir/water/oil detection, 𝑅=7 mm, 𝜀=0.23 mm, self-referencing sensor; ^bdiscrete multipoint fuel level sensor, stripped fibre, gauge-shape bend.
^cAir/water/oil detection, 𝑅=25 mm, 𝜀=0.23 mm, self-referencing sensor; ^ddiscrete multipoint fuel level sensor, polished fibre, no bend.
^eDiscrete multipoint fuel level sensor, stripped fibre, helicoidal bend; ^fair/water/oil detection, 𝑅=60 mm, 𝜀=0.21 mm, self-referencing sensor.