Knowledge of experimentally obtained values of elastic deformations of rubber springs induced by applied compressive forces of known magnitudes is essential for the selection of rubber springs with optimal properties, which are used in vibration machines. This paper deals with the laboratory measurement of the characteristics of rubber springs using two types of sensors that sense the instantaneous value of the compressive force acting on the compressed spring. By sensory monitoring of the pressure forces acting on the springs supporting the trough of vibratory conveyors, it is possible to analyse, diagnose and automate the working operation of vibration machines in practice. The characteristics of eight types of rubber springs were measured in two ways on laboratory equipment, and the spring stiffnesses were calculated from the measured data. Experiments have shown that the actual stiffnesses of rubber springs are lower compared to the values stated by the manufacturer, in the least favourable case by 33.6%. It has been shown by measurements that at the beginning of the loading of the rubber spring, its compression is gradual, and the stiffness increases slowly, which is defined as the progressivity of the spring.