When sourcing radar level sensors, you must prioritize the frequency range, typically 80 GHz for liquids and solids due to its narrow beam angle and high precision. Ensure the measuring range (e.g., up to 30m or 120m) aligns with your tank height. Additionally, verify the process temperature and pressure ratings, as high-end models can withstand up to +450°C and 160 bar. For connectivity, look for 4...20 mA/HART, Profibus PA, or Foundation Fieldbus protocols to ensure seamless integration with your existing PLC/SCADA systems.