09,18,2026 11 views
Ultrasonic level gaugeVS Radar Level Gauge: A Comprehensive Comparison from Measurement Blind Spot to Anti Interference Capability
Ultrasonic level gauge, Chuchen Technology is a professional manufacturer of ultrasonic level gauges, and ultrasonic level gaugesJ grid discount, offer discounts for large quantities! This instrument contains multiple self-developed Z-li technologies and has a brand new signal processing technology. It has the characteristics of safety, cleanliness, high accuracy, long service life, stability and reliability, easy installation and maintenance, and simple reading. It is widely used in industries such as petroleum, chemical, water treatment, water conservancy, steel, coal mining, power, and food processing, and is suitable for various fields such as acid, alkali, salt, anti-corrosion, high temperature, and explosion prevention. This instrument can be connected to various DCS systems through 4-20mA or RS485 (Modbus protocol), providing real-time liquid level data for industrial automation operation.
In the field of industrial liquid level measurement, ultrasonic level gauges and radar level gauges are two mainstream non-contact measurement devices, both of which rely onThe advantages of "no contact with media and easy installation" are widely used in chemical, water conservancy, environmental protection, food and other scenarios. However, in actual selection, users often have insufficient understanding of the core differences between the two, such as measurement blind spots, anti-interference ability, and environmental adaptability, resulting in "wrong selection and poor use" of the equipment. This article will start fromPrinciple traceabilityDepart, revolve aroundMeasuring blind spotsThe two core dimensions of "anti-interference ability" are comprehensively compared based on key parameters such as range, environmental adaptability, and cost. At the same time, scenario based selection suggestions are attached to provide reference for practical applications.
1、 Principle traceability: The fundamental difference between mechanical waves and electromagnetic waves determines the underlying logic of performance
To understand the difference between the two, it is necessary to first clarify the essential difference in their measurement principles——This is the core root cause of the subsequent blind spots and different anti-interference capabilities.
1. Ultrasonic level gauge: relies on the "reflection reception" of mechanical waves
Ultrasonic level gauge passed throughPiezoelectric transducerConvert electrical energy into mechanical waves (typically with a frequency of)20kHz-200kHz）， Mechanical waves propagate along air or gas media to the liquid surface and are reflected. The transducer then converts the reflected echo into electrical energy. By calculating the time difference between transmission and reception, combined with the propagation speed of sound waves in the medium (temperature compensation is required), the liquid level height is finally calculated. The formula is:
liquid level height=Probe installation height - (sound speed x time difference)/2
Its core dependencyPropagation and Reflection of Mechanical WavesAffected by the medium (air)/The density, composition, and flow state of gases have a significant impact.
2. Radar level gauge: relying on the "penetration reflection" of electromagnetic waves
Radar level gauge (mostly pulse radar or frequency modulated continuous wave radar)antennaTransmitting high-frequency electromagnetic waves (usually with a frequency of6GHz-80GHz， In the microwave frequency band, electromagnetic waves penetrate air/gas media and reflect off the liquid surface. The antenna receives the reflected waves and calculates the time or frequency difference between transmission and reception. Combined with the propagation speed of electromagnetic waves in vacuum (constant at 3 × 10 ⁸ m/s, almost unaffected by the medium), the liquid level height is calculated
liquid level height=Probe installation height - (electromagnetic wave velocity x time difference)/2
Its core dependencyPropagation and Reflection of Electromagnetic WavesDue to the strong penetration and stable propagation speed of electromagnetic waves, they are much less affected by environmental media than ultrasonic waves.
2、 Core Comparison 1: Measurement Blind Spot——The difference from 'cause' to 'actual impact'
The 'measurement blind spot' refers to the area below the device probe that cannot be accurately measured, which directly determines the 'Z-low measurable liquid level' and is a key indicator for the selection of small range storage tanks and closed containers. The blind spot difference between the two mainly comes from the principle characteristics and hardware design.
1. Comparison of causes of blind spots
comparative dimension |
Ultrasonic level gauge |
radar level gauge |
Core reasons |
Mechanical waves existResidual vibration effect ": After the transducer emits mechanical waves, it needs a certain period of time to stop vibrating before it can receive echoes, during which it cannot recognize close range echoes |
Electromagnetic waves existClose range signal interference: The transmitted signal and received signal will overlap with each other at close range, causing the signal to be indistinguishable |
influencing factors |
1. Probe frequency: The higher the frequency, the shorter the residual vibration time, and the smaller the blind spot (such as a 200kHz probe blind spot ≈ 0.2m, a 20kHz probe blind spot ≈ 0.5m). 2. Range: The larger the range, the larger the blind spot is usually |
1. Antenna type: Horn antenna blind zone>Parabolic antenna blind zone (e.g. 6GHz horn antenna blind zone ≈ 0.3m, 26GHz parabolic antenna blind zone ≈ 0.1m) 2. Transmission power: The lower the power, the smaller the blind zone (low-power models have better blind zones) |
Typical blind spot range |
Regular model:0.2m-1.0m (large range models can reach up to 1.5m) |
Regular model:0.1m-0.5m (high-frequency small range models can be as low as 0.05m) |
2. Practical application impact and selection suggestions
·Small range scenarios (such as0-2m laboratory storage tank, small batching tank：
Blind spot of ultrasonic level gauge（If the proportion of 0.2m-0.5m is too high, it may lead to the inability to measure the low liquid level of "Z" (if the actual liquid level needs to be measured at 0.1m, the ultrasonic blind zone of 0.2m cannot be covered); Radar level gauges (with blind spots below 0.1m) are more suitable and can accurately measure liquid levels at close range.
·Medium to large range scenarios (such as0-10m industrial liquid storage tank, 0-30m hydraulic water tank：
Blind spot of ultrasonic level gauge（The proportion of 0.5m-1.0m is low (only 5% -3.3%), which has a relatively small impact on the overall measurement; Although the radar level gauge has a smaller blind spot, its cost is higher, and in this case, ultrasound has a better cost-effectiveness.
·Closed container scenarios (such as high-pressure reactors, vacuum tanks)：
The mechanical waves of ultrasonic level gauges are affected by the gas density inside the container, which may cause fluctuations in blind spots; Radar level gauges have stable electromagnetic wave propagation, more fixed blind spots, and more reliable measurements.
3、 Core Comparison 2: Anti interference Capability——Performance showdown under 6 typical interference sources
The interference sources (dust, steam, foam, electromagnetism, temperature, medium volatiles) on the industrial site directly affect the stability of equipment measurement. The difference in anti-interference ability between the two is the core basis for the selection of complex working conditions.
Performance comparison under 6 major interference sources
Type of interference source |
Performance of ultrasonic level gauge |
Performance of radar level gauge |
Advantages and disadvantages conclusion |
Dust environment(such as mining silos, cement storage tanks) |
Mechanical waves are easily scattered by dust particles, resulting in weakened or lost echo signalsFalse alarms of "no liquid level" and "false liquid level"; Requires "dust cover+signal filtering algorithm", but the effect is limited (measured when dust concentration>50mg/m ³)W difference＞5%） |
Electromagnetic waves have strong penetrability, and dust hardly affects propagation (only high concentration dust<Slight attenuation at 1000mg/m ³); No additional protection required, measurementW difference＜1% |
radar level gaugesignificantly better thanUltrasonic waves are used in dust scenesS selection |
Steam environment(such as boiler water tank, high-temperature reactor) |
Steam can change the density of air, causing fluctuations in the propagation speed of mechanical waves (with temperature changes)At 1 ℃, the sound velocity changes by about 0.6m/s, and steam condenses on the surface of the probe, affecting wave emission; It is necessary to install an "anti condensation probe+temperature compensation algorithm", but it is still prone to failure under high temperature steam (>100 ℃) |
Electromagnetic waves are not affected by steam density and are resistant to high temperaturesThe surface of the antenna (150 ℃ -200 ℃) has undergone anti condensation treatment, resulting in stable signals; Only ultra-high temperature steam (>300 ℃) requires special high-temperature resistant antennas |
radar level gaugesuperior toUltrasonic waves, a must-have for high-temperature steam scenes |
Foam environment(such as sewage treatment aeration tank, beer fermentation tank) |
1. Thin foam (<5cm): low-frequency probe (20kHz -50kHz) can penetrate, and the measurement is basically stable; 2. Thick foam (>5cm): mechanical wave is absorbed by foam without echo; Need to be equipped with waveguide, but increase installation cost |
1. Low dielectric constant foam (such as beer foam, ε r ＜ 1.5): electromagnetic wave can penetrate and the measurement is stable; 2. High dielectric constant foam (such as electrolyte containing sewage foam, ε r>3): foam will reflect electromagnetic waves, leading to "false high liquid level"; Select parabolic antenna to focus signal |
Thin foam scene both, thick foam/High dielectric foam scene radarbetter(Select the right antenna type) |
electromagnetic interference(such as near frequency converters or high-voltage equipment) |
Mechanical wave propagation is not affected by electromagnetic waves, only electronic components may be subjected to strong electromagnetic forces (＞1000V/m) interference; Choose a model with electromagnetic shielding (EMC rating ≥ EN 61326) to ensure stable operation |
Electromagnetic waves are susceptible to strong electromagnetic interference (such as high-frequency radiation from frequency converters and high-voltage arcs), leading to an increase in signal clutter; Need to choose highEMC rating (≥ EN 61326 Class B)+anti-interference antenna, otherwise measureW differencebig |
Ultrasonic level gaugesuperior toRadar, Strong Electromagnetic SceneS selection |
temperature fluctuation(such as-30 ℃ low-temperature storage tank, 120 ℃ high-temperature asphalt tank) |
Temperature affects the propagation speed of mechanical waves (per± 10 ℃, sound velocity variation ± 6m/s), dependent on temperature compensation algorithm; However, the piezoelectric ceramic performance of the probe decreases at ultra-low temperatures (<-20 ℃), and electronic components are prone to aging at ultra-high temperatures (>80 ℃) |
The propagation speed of electromagnetic waves is not affected by temperature, only the antenna material needs to be adapted to the temperature (e.g-Conventional antenna at 40 ℃ -150 ℃, high-temperature antenna at -60 ℃ -250 ℃); The impact of temperature fluctuations on measurement accuracy is less than 0.1% FS |
J-end temperature scene radarsuperior toultrasonic wave |
Volatile substances in the medium(such as chemical solvent tanks, alcohol storage tanks) |
Volatile substances may corrode the probe material (such as ordinary ones)The ABS probe is corroded by organic solvents, and the volatile substances change the air composition, affecting the sound velocity; PTFE anti-corrosion probe and regular calibration of sound speed are required, resulting in high maintenance costs |
Volatile substances hardly affect the propagation of electromagnetic waves, only the antenna material needs to be adapted (e.gPTFE coated antenna anti-corrosion); No need for frequent calibration, low maintenance cost |
High volatility/Strong corrosion scene radarsuperior toultrasonic wave |
2. Summary of anti-interference ability: scene adaptation priority
·Prioritize the scenario of selecting radar level gauges: dust, high-temperature steam, thick foam, high volatile corrosionJ-end temperature (＜ -20 ℃ or ＞ 80 ℃);
·Prioritize the scenario of selecting ultrasonic level gaugesStrong electromagnetic interference (frequency converter)/High pressure equipment), thin foam (<5cm), medium and large range normal temperature and pressure scenarios;
·Scenarios that require special design: High dielectric foam (paraboloid antenna is selected for radar), high-pressure airtight container (high-pressure model is required for both, but radar is more stable).
4、 Comparison of other key parameters: range, cost, installation and maintenance
In addition to blind spots and anti-interference, parameters such as range, cost, installation difficulty, and maintenance cycle are also important considerations when selecting.
parameter type |
Ultrasonic level gauge |
radar level gauge |
measurement range |
Regular model:0.2m-15m (air medium); Special model: 0.5m-30m (requires low-frequency probe) |
Regular model:0.1m-30m (horn antenna); Special model: 0.05m-100mm (parabolic antenna+high power) |
Cost level |
Procurement cost: mid to low end（1000-3000 yuan), G-end anti-corrosion model (3000-5000 yuan); Operation and maintenance cost: Calibrate once every 6 months, and replace the probe if it is vulnerable (with an average annual cost of about 500 yuan) |
Procurement cost: mid to low end（3000 yuan -8000 yuan), G-end high-frequency model (8000 yuan -20000 yuan); Operation and maintenance cost: Calibrate once every 1-2 years, with a long antenna lifespan (average annual cost of about 200 yuan) |
Installation difficulty |
Strict vertical installation is required (tilted>5 ° isW differenceIncrease), avoid obstacles (such as brackets, feeding pipes); Split type models require power cords to be installed +Signal line, installation is slightly complicated |
High tolerance for installation angles (tilt<15°W difference＜0.5%), with minimal impact from obstacles (parabolic antennas can avoid them); Wireless models (LoRa/4G) do not require wiring, making installation more convenient |
Media compatibility |
Not applicable to volatile substances in high viscosity media and high concentration dust gases; For a vacuum environment (with a sound velocity of)0) Complete failure of W |
Suitable for almost all media (except pure metal liquid surface, electromagnetic waves are prone to total reflection); Suitable for both vacuum and high-pressure environments |
5、 Summary: Selection Decision Tree and Scenario based Recommendation
Based on the above comparison, you can pressBuild a selection decision tree based on "scene priority" to quickly match suitable devices:
1. Selection decision tree
1. whetherJ-end scenario(Dust)/High temperature steam/thick foam/ultra-low temperature/high corrosion) → Yes → select radar level gauge (antenna type and temperature class need to be confirmed);
1. Is it a small-scale scenario（0-2m) → Yes → Select radar level gauge (with smaller blind spots);
1. Is it a strong electromagnetic scenario(Frequency converter)/Next to high-voltage equipment) → Yes → Select ultrasonic level gauge (better resistance to electromagnetic interference);
1. Is it a medium to large range ambient temperature and pressure scenario（0-15m， No complex interference) → Yes → Choose ultrasonic level gauge (with higher cost-effectiveness);
1. Is it a vacuum/High voltage scenario→ Yes → Select radar level gauge (stable electromagnetic wave propagation).
2. Recommended Typical Scenarios
·case1: Mining cement silo (0-10m, high dust)Select a 26GHz parabolic antenna radar level gauge (blind zone of 0.1m, anti dust interference);
·case2: Chemical acid and alkali storage tank (0-5m, strong corrosion+room temperature)→ Choose PTFE probe ultrasonic level gauge (cost 3000 yuan, 50% less than radar);
·case3: Sewage treatment aeration tank (0-3m, thin foam+strong electromagnetic)→ Select low-frequency (40kHz) ultrasonic level gauge (anti electromagnetic+penetrating thin foam);
·case4: Laboratory pharmaceutical storage tank (0-1m, high-precision)→ Select a 60GHz high-frequency radar level gauge (blind zone 0.05m, accuracy ± 0.1% FS);
·case5: Water conservancy reservoir (0-20m, normal temperature+large range)→ Choose a regular ultrasonic level gauge (cost 2000 yuan, meets measurement requirements).
Conclusion: No“ZY”Only 'most suitable'
Ultrasonic level gauge and radar level gauge are notThe opposing relationship of "who is better than whom" is based on the adaptation selection of "principle characteristics scene requirements":Ultrasonic level gauges are suitable for medium to large range, normal temperature and pressure, low interference scenarios, with outstanding cost-effectiveness; Radar level gauges are suitable for complex interference, small rangeJ-end environment scenario, with better stabilityIn actual selection, it is necessary to considerThe four elements of "blind spot demand interference type range cost budget" are comprehensively judged. If necessary, equipment performance can be verified through "on-site testing" to ensure accurate selection and avoid problems such as "buying at a high price wrong" or "low price failure".
