# Design and Testing of a Measurement Device for High-Speed Bearing Evaluation
## 2 Materials and Methods
### Measurement Stand  
To ensure optimal and precise working conditions for complex testing, a special measurement stand was designed and constructed. This stand became a key tool in this research because it allowed us to conduct detailed tests aimed at understanding the impact of nanoparticle additives on the physical properties of rolling bearings. The main goal was to gain thorough insights into these properties and their changes through the use of nanoparticle additives [26].  
The measurement stand was designed with careful consideration of the requirements of research and was inspired by equipment used in the textile industry (Figure 3). This means that the inspiration came from existing technologies and was adapted to the requirements of the described experiment. This solution was suitable because the textile industry is an area where rolling bearings are widely used and exposed to various operational conditions.  
The created measurement stand consists of four separate chambers, which are used to heat rolling bearings to their operating temperature. This is crucial because temperature significantly influences the behavior and physical properties of bearings. One of these chambers is used to measure the monitored parameters.  
The control of the rotational speed of the tested bearing is provided by an electric motor. In the case of the created design, an asynchronous electric motor controlled by a frequency converter was selected [27]. To achieve the desired rotational speed, scalar control with feedback based on speed sensing was chosen. As is well known, this type of closed-loop control (Figure 4) is a reliable solution for starting asynchronous rotating machines and maintaining their speed [28].  
Figure 4: Block diagram of scalar control of an asynchronous motor.  
Figure 3: Measurement stand for testing textile bearings.  
The identification of the actual rotational speeds of the bearings was carried out using an optical probe (Figure 5) by sensing the speeds of the rotating mechanism coupled to the shaft of the measured bearing. This choice allowed us to set the speeds of the tested bearings precisely and variably, which was essential for the research. By adjusting the speeds, various operating conditions could be simulated and the impact of nano-particle additives at different speeds on the operational characteristics of the rolling bearings could be verified.  
The following equipment for data collection was used:  
* A vibration sensor (Figure 6--left) with a range up to 10 kHz labeled as MTN/2200S. It is a universal constant current accelerometer with a side input and an isolated AC output, made from durable stainless steel for long-term vibration analysis in harsh environments. A vibration sensor (Figure 7--right) with a range up to 60 kHz was labeled as 352A60.  
Figure 5: Placement of the rotation measurement probe.  
* A portable data collector/FFT analyzer called Microlog GX, designed for monitoring or analyzing vibrations with recording capability. It allows for easy condition monitoring of equipment in industries such as paper, energy, petrochemical, and others. It includes vibration signals and process variables in a range from 10 cycles per minute (0.16 Hz) to 2,400,000 cycles per minute (40 kHz).
* Specialized software for collecting and analyzing dynamic data on the LabView platform (Figure 7).