The brake linkage of a hoisting machine is a very important component determining the safety of the hoisting machine’s entire braking system. It is subject to weekly inspections. However, an efficiency test of brake performance is carried out every 6 months. Once every 3 years, a test must be carried out by an appraiser who pays particular attention to the executive and control components of the brakes as well as the strain - brake system and brake release components. The legal provisions regulating the testing of braking system linkages are not precise. So far, the control has been based on random measurement of strains using electrical resistance strain gauges stuck to the surface of the linkage. A new method for measuring the strains of the linkage has been proposed in the work. It is based on fibre optic strain sensors with Fibre Bragg Gratings (FBG). They are mounted using specially designed and tested holders for mounting on the brake linkage. They provide quick assembly and the measurement of strain in the direction parallel to the axis of the linkage. The structure of the holder also allows for the measurement in 4 positions turned every 90 relative to one another. Such a measurement enables a comprehensive analysis of strains and stresses in the brake linkage. In the work, it was shown that there is a complex state of strain and stress in the brake linkage. The previous procedures for linkage testing are inadequate in relation to this condition. An experimental and numerical method was proposed to assess the state of linkage stress. It should constitute the basis for the decision of the appraiser to allow the linkage for further use. The method proposed in the work also allows for continuous measurements of linkage strains as well as dynamic braking tests.
The paper presents a construction of a system for measurements of pH, concentration of calcium ions and concentration of heavy metal ions in water. Three fiber optic sensors in flow configuration were designed and tested. The system is fully automatic and can be used for water quality monitoring.