Radiation detectors, such as survey meters, are essential for ensuring radiation safety in various sectors, including healthcare, industrial processing, emergency response, etc. However, regular calibration and proper...Radiation detectors, such as survey meters, are essential for ensuring radiation safety in various sectors, including healthcare, industrial processing, emergency response, etc. However, regular calibration and proper maintenance of survey meters are important in order to ascertain their accuracy and reliability. This study provides a comprehensive retrospective assessment of the calibration behaviour, durability, and fault trends of 160 survey meters, spanning ten different models. They were calibrated at the Secondary Standard Dosimetry Laboratory (SSDL) in Nigeria over a decade (2012-2023) using an X-Ray Beam Irradiator Model X80-225K and Cs-137 irradiator (OB6) with a PTW reference spherical chamber traceable to the IAEA SSDL in Seibersdorf, Austria. The calibration stability of each model was evaluated, revealing that models like Instrument A and Instrument B demonstrated high reliability with calibration factors close to the ideal value of 1, while models like Instrument C exhibited higher variability, suggesting less consistent performance for dose rate monitoring. Fault analysis showed that the most common issues were related to the battery compartment, indicating a need for improved handling practices. Correlation analysis reveals no statistically significant correlation between calibration factor and age of survey meter across the analysed models. The study concludes that regular calibration, proper handling, and user training are crucial for maintaining the accuracy and longevity of radiation detectors.展开更多
Vibration intensity and non-dimensional amplitude parameters are often used to extract the fault trend of rotary machines. But,they are the parameters related to energy,and can not describe the fault trend because of ...Vibration intensity and non-dimensional amplitude parameters are often used to extract the fault trend of rotary machines. But,they are the parameters related to energy,and can not describe the fault trend because of varying load and conditions or too slight change of vibration signal. For this reason,three non-dimensional parameters are presented,namely waveform repeatability factor,waveform jumping factor and waveform similarity factor,called as waveform factors jointly,which are based on statistics analysis for the waveform and sensitive to the change of signal waveform. When they are used to extract the fault trend of rotary machines as a kind of technology of instrument and meter,they can reflect the fault trend better than the vibration intensity,peak amplitude and margin index.展开更多
文摘Radiation detectors, such as survey meters, are essential for ensuring radiation safety in various sectors, including healthcare, industrial processing, emergency response, etc. However, regular calibration and proper maintenance of survey meters are important in order to ascertain their accuracy and reliability. This study provides a comprehensive retrospective assessment of the calibration behaviour, durability, and fault trends of 160 survey meters, spanning ten different models. They were calibrated at the Secondary Standard Dosimetry Laboratory (SSDL) in Nigeria over a decade (2012-2023) using an X-Ray Beam Irradiator Model X80-225K and Cs-137 irradiator (OB6) with a PTW reference spherical chamber traceable to the IAEA SSDL in Seibersdorf, Austria. The calibration stability of each model was evaluated, revealing that models like Instrument A and Instrument B demonstrated high reliability with calibration factors close to the ideal value of 1, while models like Instrument C exhibited higher variability, suggesting less consistent performance for dose rate monitoring. Fault analysis showed that the most common issues were related to the battery compartment, indicating a need for improved handling practices. Correlation analysis reveals no statistically significant correlation between calibration factor and age of survey meter across the analysed models. The study concludes that regular calibration, proper handling, and user training are crucial for maintaining the accuracy and longevity of radiation detectors.
文摘Vibration intensity and non-dimensional amplitude parameters are often used to extract the fault trend of rotary machines. But,they are the parameters related to energy,and can not describe the fault trend because of varying load and conditions or too slight change of vibration signal. For this reason,three non-dimensional parameters are presented,namely waveform repeatability factor,waveform jumping factor and waveform similarity factor,called as waveform factors jointly,which are based on statistics analysis for the waveform and sensitive to the change of signal waveform. When they are used to extract the fault trend of rotary machines as a kind of technology of instrument and meter,they can reflect the fault trend better than the vibration intensity,peak amplitude and margin index.
