1. Working Principle
Ultrasonic Level Meter
Adopts non-contact measurement. The sensor emits ultrasonic pulses, which reflect back when they hit the liquid surface. The controller calculates the liquid level height by measuring the travel time of the sound waves (based on the speed of sound in air).
Static Pressure (Submersible) Level Transmitter
Uses the hydrostatic pressure principle. The probe is directly immersed in the liquid; the pressure exerted by the liquid on the sensor diaphragm is proportional to the liquid depth. The pressure signal is converted into an electrical signal to obtain the real-time liquid level.
2. Installation & Contact Mode
Ultrasonic Level Meter
- Non-contact installation: mounted above the tank, pit or open container, no direct contact with the liquid.
- Easy to install, no need to cut the pipeline or drill holes at the tank bottom.
- Ideal for corrosive, sticky, dirty liquids or liquids containing solid particles (no risk of probe contamination).
Static Pressure Level Transmitter
- Contact measurement: the probe must be submerged in the liquid.
- Installation requires placing the sensor into the medium from the top or bottom of the tank/container.
- Not suitable for highly viscous liquids, as the probe is prone to being covered by sludge, sediment or viscous substances.
3. Environmental Adaptability
Ultrasonic Level Meter
- Affected by environmental factors such as temperature changes, steam, fog, dust, and foam on the liquid surface.
- Not recommended for sealed tanks with heavy vapor, strong foam, or high dust environments.
- Suitable for open pools, rivers, clean water tanks, and general sewage (with little foam).
Static Pressure Level Transmitter
- Not affected by steam, foam, dust, or air temperature (measurement is independent of air conditions).
- Stable measurement in sealed tanks, dark tanks, high humidity, and other harsh environments.
- Can work stably in media with slight sediment (regular cleaning is required).
4. Medium Suitability
Ultrasonic Level Meter
Suitable for: clean water, sewage, river water, chemical liquids without heavy foam.
Not suitable for: high-viscosity oil, dense foam, easy-crystallization media (may block or interfere with sound wave transmission).
Static Pressure Level Transmitter
Suitable for: water, wastewater, oil, chemical media, sewage with sediment, and slightly corrosive liquids (with proper probe material: 304/316L, PVDF).
Not suitable for: media with strong corrosiveness (without special material modification) or highly viscous media that easily clog the diaphragm.
5. Maintenance & Service Life
Ultrasonic Level Meter
- No wearing parts, almost maintenance-free.
- No contact with the medium, no pollution, and long service life.
- Only need to regularly clean the probe surface to avoid dust or dirt blocking the sound wave emission.
Static Pressure Level Transmitter
- The diaphragm is easy to be blocked or contaminated by sludge, sediment, or viscous media.
- Requires regular cleaning, inspection, and calibration to ensure measurement accuracy.
- Diaphragm aging may affect long-term measurement stability, requiring periodic replacement.
6. Accuracy & Cost
Ultrasonic Level Meter
- Medium accuracy (usually ±0.5%~±1.0% FS), sufficient for most water industry applications.
- Simple structure, moderate cost, cost-effective for non-contact measurement scenarios.
Static Pressure Level Transmitter
- High measurement accuracy (usually ±0.1%~±0.5% FS), stable reading, suitable for scenarios requiring precise measurement.
- Lower cost than ultrasonic meters in many low-range (≤10m) applications.
- Good cost performance for long-term fixed monitoring of sealed tanks or deep liquid levels.
7. Key Summary for Support
When responding to customer inquiries, focus on the following core points based on their actual needs:
- If the customer needs non-contact measurement (to avoid medium contamination), recommend ultrasonic level meters.
- If the customer uses a sealed tank, has high foam/steam, or requires high measurement accuracy, recommend static pressure level transmitters.
- For viscous, dirty media with sediment, static pressure meters are more suitable (with regular maintenance); for corrosive media, confirm the probe material first.
- Ultrasonic meters are easier to install and maintain; static pressure meters are more stable in harsh air environments.
Post time: May-07-2026