Choosing the appropriate type of radar level gauge requires comprehensive consideration of factors such as medium characteristics, measurement environment, accuracy requirements, and cost. The following is a systematic selection guide:1、 Analysis of Core Selection Dimensions1. Medium characteristics: the fundamental factor determining the technological routeDielectric constant (ε r)High dielectric constant (ε r>10): Suitable for water, strong acids, strong bases, etc. Pulse radar or intelligent radar can be selected (non-contact type is sufficient).Medium to low dielectric constant (ε r=1.4-10): For petroleum, liquefied gas, dry powder, etc., guided wave radar (enhancing reflection signals through guided wave rods) or FMCW radar (high-precision capture of weak reflections) is preferred.Extremely low dielectric constant (ε r<1.4): For liquefied natural gas (LNG), FMCW radar (with strong resolution) or customized guided wave radar (cable type guided wave rod) is required.physical stateLiquid: Non contact (pulse/FMCW) or guided wave can be used, and guided wave is preferred for viscous liquids (to avoid antenna hanging).Solid particles/dust: For dust environments, choose guided waves (guided wave rods to resist dust interference), and for particle silos, choose pulse radar (with a large range).Corrosive/Toxic: Strong corrosive media (such as concentrated hydrochloric acid) must be selected non-contact (pulse/FMCW), and the antenna material must be matched (such as PTFE coating).2. Measurement environment: affecting installation and anti-interference designcontainer typeOpen container/outdoor storage tank: Choose pulse radar (wide range, resistant to environmental clutter).Container with mixing/baffle: guided wave radar (guided wave rod installed along the wall to reduce mixing interference) or FMCW (algorithm suppression interference).Small diameter pipelines/narrow spaces: Guided wave radar (the length of the guided wave rod can be customized to adapt to narrow spaces).Environmental interferenceDust/Steam: Guided wave radar (guided wave rod conducts signals to reduce the scattering effect of dust).High temperature and high pressure (such as>200 ℃ or>10MPa): For non-contact radar (pulse/FMCW), the temperature and pressure resistance level of the antenna needs to be confirmed (such as ceramic antennas that can withstand temperatures up to 400 ℃).3. Accuracy and Range Requirements: Matching Technical Parametersmeasurement accuracy High precision scenario (± 1-3mm): Chemical reaction kettle liquid level control, pharmaceutical raw material measurement, choose FMCW radar or high-end intelligent guided wave radar.Medium precision (± 10mm): For ordinary storage tanks and silos, choose pulse radar or conventional intelligent radar.Measurement rangeLarge range (>50 meters): For large oil storage tanks and blast furnace material levels, pulse radar (with a range of up to 100 meters or more) or FMCW (requires confirmation of * large range) should be selected.Small range (<10 meters): For small containers and pipelines, choose guided wave radar (with a minimum range of 0.3 meters).4. Cost and Maintenance: Balancing Cost Performance and ReliabilityInitial cost: FMCW radar (* high)>intelligent radar>pulse radar ≈ guided wave radar.Maintenance cost: Non contact (pulse/FMCW) maintenance frequency is low (no mechanical wear), and the guided wave radar needs to be regularly checked for scaling on the guide rod (especially for viscous media).Long term reliability: Non contact type is preferred for harsh working conditions (such as strong corrosion and high dust) to reduce the risk of equipment damage.2、 Typical scenario selection case1. Petrochemical storage tank (medium: crude oil, ε r ≈ 2.5, range of 30 meters)Recommendation: Guided wave radar (cable type) or pulse radar.Reason: The low dielectric constant of crude oil enhances the signal with a waveguide rod; Moderate range, non-contact pulse radar to avoid corrosion, and resistant to oil and gas vapor interference.2. Pharmaceutical reaction kettle (medium: drug solution, ε r>10, accuracy ± 2mm, with stirring)Recommendation: FMCW radar (non-contact).Reason: High precision is required to match the ± 1mm accuracy of FMCW; The FMCW algorithm in a stirred environment can filter interference and avoid drug adhesion to the antenna in a non-contact manner.3. Cement silo (medium: dry cement powder, ε r ≈ 3, high dust, measuring range of 50 meters)Recommendation: Guided wave radar (pole type) or pulse radar.Reason: Guided wave rods have strong anti-interference ability in dusty environments; If the diameter of the silo is large (>10 meters), the wide beam of the pulse radar can cover a larger range.4. Liquefied natural gas (LNG) storage tank (medium: LNG, ε r ≈ 1.2, -162 ℃ low temperature)Recommendation: FMCW radar (low-temperature type).Reason: Extremely low dielectric constant requires high-resolution FMCW signal capture; Special low-temperature resistant antennas (such as stainless steel materials) are required for low-temperature environments, and FMCW non-contact design is used to avoid mechanical failures at low temperatures.