GUIDED WAVE RADAR LEVEL SENSORS: CALIBRATION AND ENVIRONMENTAL IMPACTS

This study presents a detailed uncertainty analysis for guided wave radar level sensors, focusing on the calibration schemes and environmental influence factors. Guided wave radar level sensors are used in numerous industrial applications, especially for harsh environmental conditions. While some of the sensors are designed for technological operations control and do not require extreme precision levels, there are applications where a high level of precision is crucial. The analysis highlights the impact of environmental factors, such as temperature, pressure, and air humidity, on measurement accuracy and calibration effectiveness. Key uncertainty contributions–including those from reference instruments, random noise (signal-to-noise ratio impact), nonlinearity, and dielectric constant variability–are assessed under reference and extended environmental conditions. Results demonstrate that under controlled environments, measurement uncertainties remain within acceptable thresholds. However, when significant environmental variability is introduced, contributions from dielectric constant changes and time estimation noise amplify uncertainty bands, especially for long-range measurements. Practical calibration recommendations are provided to maintain measurement accuracy in controlled and harsh operational conditions. Additionally, the study compares scenarios using high-accuracy calibration setups with cost-effective alternatives for non-critical applications. These comparisons guide sensor manufacturers and metrological regulators in optimizing calibration practices while balancing cost and performance. The findings underscore the importance of compensating for dielectric constant variability in dynamic environments. Future work should explore uncertainty reduction techniques, including real-time correction. The provided insights are instrumental for improving polymetric sensor systems and ensuring reliable level measurements in diverse applications, fostering advancements in industrial automation and process control.