Precipitation Sensors / RainVue 20
RainVue 20 SDI-12 Precipitation Sensor with Aluminum Funnel
Simple and Robust Digital Sensor
weather applications water applications energy applications gas flux and turbulence applications infrastructure applications soil applications


The RainVue™️20 is ideal for many hydrological or meteorological applications such as weather stations and flood warning systems. The RainVue 20 is an SDI-12 tipping bucket rain gage in the RainVue family of products. Advanced algorithms and digital processing within the sensor compensate for errors caused by high-intensity rain and provide accurate precipitation and intensity measurements. Constructed of an aerodynamic powder-coated aluminum funnel, the RainVue 20 is robust and minimizes the amount of liquid precipitation that is lost due to the effects of wind. This rain gage offers the user flexibility with the option to select from a series of set cable lengths or a user-defined cable length.

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Benefits and Features

  • Powder-coated aluminum bucket suitable for all environments
  • Extremely robust and versatile for applications where data precision and accuracy are critical
  • Unique aerodynamic shape to minimize wind effects and increase accuracy
  • Measures precipitation intensity up to 1500 mm/h (60 in./h)
  • Meets WMO recommendations for funnel area
  • Digital processing corrects for high-intensity precipitation errors up to 1500 mm/h (60 in./h)
  • Tilt measurement for remote diagnostics on the sensor
  • Internal temperature measurement
  • Easy leveling with external leveling bubble
  • Adjustable mounting feet to simplify leveling


View of the 39668 funnel filter installed in a RainVue precipitation sensor

Detailed Description

The RainVue 20 funnels rainfall through a stainless-steel gauze filter that traps and removes debris. The rainfall flows through a nozzle into one of the two halves of the tipping bucket. The internal tipping bucket assembly rotates around precision, rolling pivot bearings. It tips when the first bucket fills to a fixed calibrated level, and then the balance arm moves the second bucket under the funnel. A magnet attached to the balance arm actuates a reed switch as the bucket tips.

The aerodynamic design of the RainVue 20 prevents wind from carrying the rainfall away from the collecting vessel. With traditional cylindrical rain gages, wind can reduce the rainfall catch by up to 20 percent. The RainVue 20 also includes a microprocessor that corrects for rainfall intensity and outputs an SDI-12 signal.

Aspen 10-Compatible IoT Solution

The RainVue 20 can be paired with the Aspen™10 Internet of Things (IoT) Edge Device. To get next-gen IoT solutions for advanced meteorological monitoring, click the image below:

RainVUE 20 + Aspen 10 Solutions


Sensor Type Tipping bucket with magnetic reed switch
  • 2 mm-thick powder-coated aluminum (for main collector body)
  • LM6 marine-grade aluminum (for base)
Output SDI-12 version 1.4
Sensor Configuration SDI-12 or USB
Operating Temperature Range
  • 1° to 70°C (liquid precipitation only)
  • -40 to +70°C (including melting snow)
Power Requirements 6 to 18 Vdc
Current Drain
  • 0.8 mA or 1 mA (active)
  • 0.07 mA (quiescent)
Internal Battery 240 mAh lithium battery (provides up to 15 days of continual operation after power loss; battery will last longer under ideal conditions)
Response Time
  • 0 s (for M0! command)
  • 1 s (for M1! command)
Measurement Uncertainty
  • Note: Accuracy over the rain intensity range requires a mechanical calibration that is within 1% at a 1 in./h intensity.

    RainVue™20 sensors are calibrated at the factory to meet this specification but should be verified prior to deployment.
  • 1° (tilt)
  • 0.25°C (temperature)
  • 0.5 V (supply voltage)
Orifice Diameter 20.0 cm (7.87 in.)
Collecting Area 314.16 cm2 (48.67 in.2)
Height 43.5 to 46.5 cm (17.1 to 18.3 in.) with feet adjustment
Weight 6 kg (13 lb)

0.01 Inch Option

Measurement Range 0 to 1200 mm/h (0 to 48 in./h)
Precipitation Amount Resolution 0.254 mm (0.01 in.)
Precipitation Amount Measurement Uncertainty 1% at 0 to 500 mm/h intensity (0 to 19.7 in./h intensity)
Precipitation Intensity Range 0 to 1200 mm/h (0 to 48 in./h)
Precipitation Intensity Measurement Uncertainty 1% at 0 to 500 mm/hh intensity (0 to 19.7 in./h intensity)
WMO Compliant No

0.1 Millimeter Option

Measurement Range 0 to 600 mm/h (0 to 23.6 in./h)
Precipitation Amount Resolution 0.1 mm (0.004 in.)
Precipitation Amount Measurement Uncertainty
  • 3.08% at 0 to 20 mm/h intensity (0 to 0.88 in./h intensity)
  • 3.6% at 20 to 600 mm/h intensity (0.8 to 23.6 in./h intensity)
Precipitation Intensity Range 0.1 to 600 mm/h (0.004 to 23.6 in./h)
Precipitation Intensity Measurement Uncertainty 3.58% at 0 to 600 mm/h (0 to 23.6 in./h intensity)
WMO Compliant Yes


Note: The following shows notable compatibility information. It is not a comprehensive list of all compatible or incompatible products.

Data Loggers

Product Compatible Note
Aspen 10
CR3000 (retired)
CR800 (retired)
CR850 (retired)

Additional Compatibility Information

The RainVue 20 is compatible with all modern data loggers and retired data loggers that support SDI-12 (CR10X, CR200).


RainVue-Series Example Program v.1 (2 KB) 10-21-2020

An example CR1000X program uses the M! SDI-12 command to measure the RainVue 10 or RainVue 20 and the XWARA! command to reset the total adjusted rain accumulator to 0.00 annually on October 1.

RainVue OS v.2.03 (474 KB) 12-07-2022

Current Operating System for the RainVue 10 and RainVue 20. Requires the Device Configuration Utility and a USB micro cable to update the OS.

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