Brookhaven National Laboratory
ARM deploys two different types of weighing buckets. Both operate on the principle of measuring the weight of liquid in a bucket as it changes over time in order to calculate the precipitation amount and rate. The weighing bucket deployed in the Arctic (AMF3) uses three vibrating wire transducers to determine the weight while the weighing bucket deployed elsewhere (SGP, ENA, AMF1, AMF2) uses a high-precision stainless steel load cell. Both gauge types employ heating techniques: the ones deployed in the Arctic are wrapped in heat tape that turns on when the orifice temperature drops below freezing, while the orifice of the other is heated for the same conditions. Both use antifreeze and oil to prevent freezing and evaporation of the liquid in the bucket, respectively. The arctic gauges are enclosed in a double alter shield that has been designed to decrease the wind flow over the orifice and increase the catch efficiency. The non-arctic gauges deploy a smaller wind shield to decrease wind effects.