Description

The weighing precipitation sensor measures the volume of water fallen as rain using a tipping bucket designed for low-viscosity liquids. The error usually caused by incomplete drainage is automatically compensated thanks to the shape of the bucket. The bucket can hold 2 cm3 (2 g) or 4 cm3 (4 g) of water.

The collecting surface area is 200 cm2 (WMO standard), so one filling of the bucket corresponds to a rainfall intensity of 0.1 or 0.2 mm per square meter. When the bucket tips, a reed switch built into the sensor closes. The pulse output data can be electrically read, transmitted, and recorded.

A signal state free of spikes can be achieved by using appropriate electrical connections. The reed switch signal can also be used directly, in which case its state will not be free of spikes.

The precipitation sensor is mounted on a base with a diameter of 60 mm, which is equipped with a connecting part for attachment to a pipe. For regions where snowfall is possible, a version of the device with a built-in heater is supplied, ensuring year-round measurements. Two independently controlled heating circuits with minimal hysteresis provide the optimal temperature, preventing snow accumulation on the sensor and minimizing evaporation from the heated surface.

The precipitation sensors are made of weather-resistant aluminum and stainless steel. This ensures a long service life of the device. These high-tech devices meet the requirements of the WMO (World Meteorological Organization).

Features

Precipitation sensor with serial output
SDI-12 (RS485) protocol for universal use
RS485 interface
Built-in intensity calibration for high measurement accuracy
Calculation of total precipitation volume since the last data transmission
Calculation of precipitation intensity over the past minute
Calculation of precipitation intensity over the past hour (minute interval)

Accessories

Boom, mud collector, protective ring, connecting cables, data logger. Power supply for sensors with heater.

In addition to the standard pulse output, other output signals are available for the sensors:

Outputs 0…20 mA, 4…20 mA, 0…5 V or 0…10 V (configurable)
Built-in intensity calibration for higher measurement accuracy

Specifications
Overall Drawing
Applications

Characteristic	Value
Measurement principle / Element	System with weighing tipping container / High-precision stainless steel container
Measurement range / Resolution	2 cm3 - (~2 g) volume of tipping container - 0.1 mm / 0…8 mm/min 4 cm3 - (~4 g) volume of tipping container - 0.2 mm / 0…16 mm/min
Accuracy	± 2% with intensity correction
Collecting funnel	200 cm2 / WMO standard
Operating ranges	Models without heating: 0…+70 °C, (frost resistance down to -20 °C) Models with heating: -20…+70 °C, no icing, no snow deposits
Pulse output	Reed contact, polarity reversal protection, free of signal spikes, supply voltage 4…30 VDC, max current consumption 100 µA, standard 50 µA, max load 30 VDC / 0.5 A
Housing / Funnel and ring material	Aluminum, anodized
Dimensions	Height 292 mm, Ø 190 mm, for mounting pipe Ø 60 mm
Weight	About 3 kg
Standards	WMO-No. 8, VDI 3786 lf. 7, EN 50081/82, VDE 0100