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


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 data loggers.

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Benefits and Features

  • Meets USGS Office of Surface Water (OSW) requirements for accuracy
  • 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
  • Low maintenance—no moving parts significantly reduces maintenance cost and time
  • Low power mode available
  • Rugged enough for harsh environments—IP68 rating
  • Optional display available

Should you need a calibration sheet, please contact Campbell Scientific prior to placing an order for the CS475A-L sensor.


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 distance (d) is from the reference line to the target

Technical Description

Features of the SDI-12 version 1.4 functionality:

  • M! commands return stage, distance, voltage, and error codes
  • SHEF coded meta data


Measurement Description Distance
Output Options SDI-12
Measurement Range 0.5 to 35 m (1.6 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)
Pulse Energy 1 mW (maximum)
Beam Angle 10°
Input Voltage 9.6 to 32 Vdc
Surge Protection 1.5 KVA
Operating Temperature Range -40° to +80°C
Vibration Resistance Mechanical vibrations with 4 g and 5 to 100 Hz
Mechanical Rating IP66/68
Housing Material Aluminum
Horn Material PVDF plastic
Measurement Time
  • < 1.0 s (normal power mode)
  • 60.0 s + (5 • Integration Time) + (Measurement Time) (low power mode)
Housing Height 129 mm (5.1 in.)
Horn Diameter 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)


Please note: The following shows notable compatibility information. It is not a comprehensive list of all compatible products.


Product Compatible Note
CR1000 (retired)
CR800 (retired)
CR850 (retired)


CS475A OS v.3.11 (458 KB) 20-06-2022

Current OS for the CS475A.

View Revision History

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