This paper presents a long-range displacement measurement method by using a single-multi-single mode (SMS) fiber structure, attached to a flexible plate between two permanent poles and the optical time domain reflectometer (OTDR)-based interrogator. The SMS fiber structure sensors are prepared with two different configurations, i.e. straight and sinusoidal configurations. It is demonstrated that the displacement sensor can perform a displacement measurement with a range from 0 mm to 150 mm with a resolution of 0.159 mm. The sinusoidal configuration provides a better sensitivity than the straight configuration. The proposed sensor offers a low cost, and it can be implemented for quasi-distributed displacement measurement which is suitable for civil structure monitoring.

This study uses a load sensor with a macro-bending on polymer optical fiber loop model which is placed between two plates with a buffer spring. The load sensor with light intensity modulation principle is an infrared LED emits light through the polymer optical fiber then received by the phototransistor and amplifier. Output voltage from the amplifier continued to arduino sequence and displayed on the computer. Load augment on the sensor resulted in an increase of curvature on polymer optical fibers that can cause power losses gets bigger too. This matter will result in the intensity of light that received by phototransistor getting smaller, so that the output voltage that ligable on computer will be getting smaller too. The sensitivity and resolution load sensors analyzed based on configuration with various amount of loops, imperfection on the jacket, and imperfection at the cladding and core of polymer optical fiber. The results showed that the augment on the amount of load, imperfection on the jacket and imperfection on the sheath and core polymer optical fiber can improve the sensitivity and resolution of the load sensor. The best sensors resolution obtained on the number of loops 4 with imperfection 8 on the core and cladding polymer optical fiber that is 0.037 V/N and 0,026 N. The advantages of the load sensor based on polymers optical fiber are easy to make, low cost and simple to use measurement methods.

The research about milk fat content based on plastic optical fiber sensor using gamma and spiral spring without cladding configurations has been reported. LED light transmitted through the plastic optical fiber to be received by the phototransistor. Changes in milk fat content affect the light intensity received by the phototransistor. Sensor output voltage amplified by a differential amplifier and then the analog signal converted into the digital signal by the Arduino Uno microcontroller furthermore, the output voltage read on a computer. The milk fat content sample with a percentage of 0.773 % to 4.473 % affect the propagation of light in the core of plastic optical fiber results in power losses that occur so that the light intensity decreases and the output voltage measured becomes smaller. The results showed that the higher the milk fat content, the sensor output voltage decreases. The best measurements obtained on the spiral spring configuration with 4 windings produce value range 0.044 V, sensitivity 11.887 mV/%, and a resolution of 0.084 %. This method is effective as well as efficiently used as milk fat sensor because it has good sensitivity and resolution.

This study aims to test of sensor based plastic optical fiber for measuring electric current and magnetic field using amacrobending technique. Sensor testing is done by using length of peel variation of with cladding and without cladding sensortype which is covered by magnetic fluid in a plastic tube. The measurement is done by putting the sensor near the magnetic field source produced by a wire coil that is electric current flowed.The magnetic field interact with the magnetic fluidthat is on the sensor resultingin the refractive index of fiber optic sensorincreases.This causes the power losses to increase and the light intensity transmitted from the LED to the phototransistor decreases so that the resulting of output voltage also decreases.The best results obtained on the with cladding sensor type with 3 cm length of peel for measuring electric current produce a sensitivity value of 0.008 V/A and a resolution of 0.121 A, while for measuring magnetic field produce a sensitivity value of 0.738 V/T and a resolution of 1.345 T.Testing of sensor based on plastic optical fiber suitable for measuring electric current and magnetic field with advantages such as having high sensitivity, easy fabrication, low cost, real time, as well as has a simplemeasurement and accurate system.

In this research, we measured heart rate by using sensors based on plastic optical fiber. These sensors are made from fiber optic material with three configurations, i.e., straight, sinusoidal, and spiral. Each sensor configuration was tested and paired in three positions of the human body, i.e., hand, chest, and neck. Each configuration and pairing position were tested for fast, normal, and slow heart rate condition. The light from the LED will propagate along the optical fiber sensor. If the sensor detects the heart rates, the intensity of light in optical fiber will be disrupted and causing loss of power so the light intensity will be smaller, it can be detected by the phototransistor and then converted into an electric voltage. The best measurement obtained in spiral configuration mounted on the neck in a slow heart rate condition with a sensitivity value 0.00231 V.s⁻¹ and a resolution 0.43203 s. This sensor has the advantage of easy fabrication, low cost, real-time measurement, high sensitivity, easy to operate and can be monitored via computer.