CS475A-L Radar Water-Level Sensor, 114.8 ft Maximum Distance
Non-Contact Water Level Monitoring
FCC approved for outdoor use
weather applications water applications energy applications gas flux & turbulence applications infrastructure applications soil applications


The CS475A radar sensor monitors the water level of rivers, lakes, tidal seas, and reservoirs. The sensor is ideal for areas where submersed sensors can be damaged due to corrosion, contamination, flood-related debris, lightning, or vandalism. It emits short microwave pulses and then measures the elapsed time between the emission and return of the pulses. The elapsed time measurement is used to calculate the distance between the sensor and the target (for example, water, grain, slurry). The distance value can then be used to determine depth of the medium.

The CS475A outputs a digital SDI-12 signal to indicate distance and stage. This output is acceptable for recording devices with SDI-12 capability, including Campbell Scientific dataloggers.

Benefits and Features

  • Meets OSW requirements for accuracy (0.01%)
  • SDI-12 version 1.4 functionality
  • Makes 1 Hz measurements
  • Monitors tides for NOAA physical oceanographic real-time systems (PORTS)
  • Easy to set up and configure over USB or SDI-12
  • FCC compliant (FCC IC# MOIPULS 616263); individual FCC license not required
  • No moving parts; significantly reduced maintenance cost and time
  • Low power mode available
  • Rugged enough for harsh environments—IP68 rating
  • Optional display available


CS475A-L attached to a pole (sold separately)
CS475A-L attached to a pole (sold separately)
CS475A-L attached to a pole (sold separately)
CS475A-L attached to a pole (sold separately)


Measurement Range 0.5 to 35 m (1.64 to 114.8 ft)
Accuracy ±2 mm (±0.0065 ft)
Resolution 1 mm (0.0033 ft)
Communications Output SDI-12 version 1.4
Radar Frequency K band (~26 GHz)
Beam Angle 10°
Input Voltage 9.6 to 32 Vdc
Operating Temperature Range -40° to +80°C
Mechanical Rating IP66/68
Housing Material Aluminum
Horn Material PVDF plastic
Housing Height 129 mm (5.1 in.)
Horn Width 115 mm (4.5 in.)
Horn Height 122 mm (4.8 in.)
Weight 2 kg (4 lb)

Nominal Current Drain

Normal Power Mode
  • < 5 mA (sleep state)
  • < 7 mA (measurement state)
Low Power Mode
  • < 550 μA (sleep state)
  • < 7 mA (measurement state)

Measurement Response Time

Normal Power Mode < 1 s
Low Power Mode 60 s + (5 • Integration Time) + (Measurement Time)


The CS475A-L is compatible with the following dataloggers: CR200(X) series, CR300 series, CR6, CR800 series, CR1000X, CR1000, CR3000, and CR5000.

The CS475A-L is not compatible with the CR9000-series or CR9000X-series dataloggers.

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