Instrument: Pluvio² Precipitation Gauge

The Pluvio² is a weighing precipitation gauge manufactured by OTT HydroMet in Germany that measures the amount and intensity of precipitation by determining its weight. It uses a high-capacity collection bucket to capture liquid, solid, and mixed precipitation types, and measure the weight of the collected water as a function of time. The system consists of a base plate with the weighing mechanism, a bucket support, a collecting bucket, and pipe housing for the pedestal that supports the gauge. The weighing mechanism is a load cell sensor housed in an airtight seal that converts the force of the collection bucket into electrical signals that can be measured. The Pluvio² comes in two models; one with a  200 cm² opening and 750 mm capacity bucket and the other with a 400 cm² opening and 1,500 mm capacity bucket (Figure 1). The standard installation height of the Pluvio² is one meter above the ground where it can collect and provide measurements of rain, snow, hail, and sleet to ± 0.05 mm accuracy for precipitation amount and ± 0.1 mm/min accuracy for intensity. The Pluvio² can operate with a 1 minute to 60 minute sampling interval, however, 1 minute is standard. 

The Pluvio² determines the precipitation intensity by measuring the difference between the current bucket weight and the previous one. These values are then added to the accumulated precipitation total. To ensure the quality of the precipitation measurements, filter algorithms are used to reduce the effects of wind, temperature, and evaporation on measurement accuracy. There is also an integrated temperature sensor that adjusts the weighing mechanism for temperature changes. The accurate measurements and low maintenance of the Pluvio² make it an ideal instrument for tasks such as estimating rainfall totals and monitoring road conditions.

Figure 1: The Pluvio² precipitation gauge 200 cm² model (left) and 400 cm² model (right)

(Image source: Nemeth, 2008)