Sensor System For Simultaneous Measurement Research Articles

Polymer-optical-fiber-based sensor system for simultaneous measurement of angle and temperature.

This paper presents a polymer-optical-fiber (POF)-based sensor system for simultaneous measurement of angle and temperature. The main contribution is obtaining a sensor with higher temperature sensitivity and lower hysteresis on the angle measurements. The annealing was made on the fibers under the conditions of low relative humidity and under water, and a third set of samples without any heat treatment was applied for comparison with the annealed ones. Results of temperature and angle characterization show that the fibers annealed under water presented higher temperature sensitivity and lower errors when compared with the fibers annealed with low humidity or the fibers without annealing. Furthermore, the fibers annealed under water also presented lower hysteresis on the angle characterization. For these reasons, such fibers were employed for the temperature and angle measurements, which results in a sensor system capable of simultaneously measuring the angle and temperature with root-mean-squared error of 0.82°C for temperature and 2.20° for angle, which is further reduced to 1.20° after the application of a dynamic compensation technique for POF curvature sensors.

Simultaneous Measurement of Strain and Temperature Using a Single Emission Line

In this study, we present and demonstrate a novel sensor system for simultaneous measurement of strain and temperature through a unique combination of a long period grating and a fiber laser based on a fiber Bragg grating. In order to achieve this, a new erbium-doped fiber laser structure is created, showing an optical signal-to-noise ratio of 55 dB and a peak power measured on the optical spectrum analyzer between −5 and 0 dBm. The strain and the temperature information can be obtained by using a unique emission line through monitoring both the fiber laser wavelength shift and the change of the power level, both of which showing a clear linear behavior.

Simultaneous measurement of strain and temperature with a multi-longitudinal mode erbium-doped fiber laser

A multi-longitudinal mode erbium-doped fiber laser sensor system for simultaneous measurement of strain and temperature is proposed and experimentally demonstrated. The beat frequency signal of the laser shifts with both strain and temperature, while, the output power of the laser only changes with temperature because of the erbium-doped fiber used in the laser cavity. By monitoring both of the beat frequency signal and the output power, the strain and temperature can be achieved at the same time. The maximum experimental errors of simultaneously obtained strain and temperature are within ±17.5με and ±1.8°C over ranges of 0–1100με and 20–140°C.

Multimode fiber laser for simultaneous measurement of strain and temperature based on beat frequency demodulation

A multimode fiber laser sensor system for simultaneous measurement of strain and temperature is proposed and demonstrated. Because of the long cavity and birefringence, longitudinal mode beat frequency and polarization mode beat frequency are achieved in the beat frequency signals of the multimode fiber laser. The strain and temperature can be obtained by monitoring both of them for their different strain and temperature responses. The experimental measurement errors are within ± 16.2 με and ± 1.9 °C. The usage of only one fiber laser and one demodulation system makes the system simple, cost-effective and portable.

Multiplexed fibre Fizeau interferometer and fibre Bragg grating sensor system for simultaneous measurement of quasi-static strain and temperature using discrete wavelet transform

We present a multiplexed fibre Fizeau interferometer (FFI) and fibre Bragg grating (FBG) sensor system for simultaneous measurement of quasi-static strain and temperature. A combined spatial-frequency and wavelength- division multiplexing scheme is employed to multiplex the FFI and FBG sensors. A demodulation technique based on the discrete wavelet transform with signal processing enhancements is used to determine the measurand- induced physical changes of the sensors. The noise associated with the sensor signal is reduced by the block-level-thresholding wavelet denoising method, which is applied via the demodulation technique. This sensor system yields a high accuracy and resolution, and low crosstalk. It is well suited for long-term quasi-static measurements, especially for the structural health monitoring of large-scale structures.

Multiplexed sensor system for simultaneous measurement of pressure and temperature

A novel multiplexed sensor system using two tunable lasers for simultaneous precise measurement of pressure and temperature is designed, tested, and simulated. The sensors are optical Fabry-Perot cavity-based pressure sensors similar to those fabricated by us using microelectromechanical systems (MEMS) techniques. This system follows a different philosophy than that followed by other multiplexing systems. We use light sources in two wavelength regions for each sensor and two interrogation methods for pressure and temperature measurement. Sensors are designed to operate over the pressure range of 0 to 30 psi and the temperature range of 25 to 90°C. This multiplexed sensor system has the potential of multiplexing about seven sensors with temperature sensitivity of 0.15 nm/°C.

Sensor System for Simultaneous Measurement of Oxygen and Hydrogen Peroxide Concentration During Glucose Oxidase Activity

An amperometric sensor system, based on a repetitive double step potential method at a glassy carbon electrode, has been developed for the simultaneous measurement of hydrogen peroxide and oxygen concentrations. The current measured at a potential of –1 V (vs. Ag/AgCl/saturated Cl–) corresponds to the sum of the reduction currents of hydrogen peroxide and dissolved oxygen. The current measured at –0.55 V (vs. Ag/AgCl/saturated Cl–) is due to the reduction of dissolved oxygen to hydrogen peroxide. Alternatively, the concentration of dissolved oxygen can also be determined using a Clark electrode. The concentration of hydrogen peroxide and dissolved oxygen during enzymatic conversion of glucose can be followed on line and be used to control the process.