Selection Guide For Radar, Guided Wave, Ultrasonic, And Capacitance Level Transmitters

Radar Level Transmitters

The radar level sensors uses 23G/80G continuous wave radar with a maximum range of 70-200 meters and a maximum blind area of 0.2 meters. The continuous wave radar has a higher operating frequency, a larger bandwidth, and better accuracy and stability than traditional low-frequency radars. The radar module adopts FMCW mode and non-contact installation design, with a small size and compact structure. It has high accuracy, low power consumption, and strong anti-interference ability. It is suitable for water level monitoring in lakes and rivers, mountain torrent warnings, reservoirs, sewage pipe networks, etc.

Features of Radar Level Transmitters

✅ High accuracy (±0.5mm)

✅ Non-contact measurement (no wear & tear)

✅ Unaffected by density, dielectric, or conductivity changes

✅ Suitable for corrosive and high-temperature environments

Limitations

⚠ Foam or turbulent surfaces can disrupt signals

⚠ Blocking distance (minimum dead zone near the sensor)

⚠ Requires proper tank geometry for optimal performance

Guided Wave Radar Level Transmitters (TDR)

Guided wave radar level transmitter uses a probe to direct radar pulses along its length. When the pulse hits the medium, part of it reflects back.

Advantages of Guided Radar

✅ Higher accuracy (±0.2mm)

✅ Works with some foam layers

✅ Unaffected by dielectric changes

✅ Ideal for small tanks or interface measurement

Limitations

⚠ Heavy foam can still interfere

⚠ Probe must be chemically compatible with the medium

⚠ Blocking distance applies

Ultrasonic Level Transmitters

Ultrasonic level sensor (measures liquid level/material level) is a non-contact, highly reliable, cost-effective, easy to install and maintain liquid level/material level measuring instrument. It can meet most liquid level/material level measurement requirements without contacting the measured medium.

Advantages

✅ Lowest cost non-contact option

✅ No calibration needed for different liquids

✅ Unaffected by density or conductivity changes

Limitations

⚠ Foam, vapor, or dust can block signals

⚠ Not suitable for vacuum or high-pressure (>44 psia) applications

⚠ Affected by temperature variations

Capacitance Level Transmitters

These measure changes in capacitance between a probe and tank wall as the level changes.

Advantages

✅ Cost-effective solution

✅ Fast response time

✅ Works in high-pressure/high-temperature conditions

Limitations

⚠ Probe coating can affect accuracy

⚠ Requires recalibration for different media

⚠ Minimum dielectric constant required (10 pF span)