The principle of weighing precipitation gauges is the measurement of weight of accumulated water via a sensitive weighing platform. A major advantage of weighing precipitation gauges is the ability to measure total precipitation–liquid or frozen–without the large power requirement of a heated inlet. However, weighing precipitation gauges can be fitted with a heated inlet to prevent snow from bridging/capping over the inlet.

SG-400: 8-inch diameter / 324 cm² area
(National Weather Service); no heater
SG-410: 8-inch diameter / 324 cm² area
(National Weather Service); heater
SG-420: 6.3-inch diameter / 200 cm² area
(World Meteorological Organization); no heater
SG-430: 6.3-inch diameter / 200 cm² area
(World Meteorological Organization); heater

Apogee Instruments SG-400 series total precipitation gauges are all-weather weighing gauges with no moving parts. They use a high accuracy load cell to measure weight of water collected in a bucket mounted on the cell. Analog to digital circuitry is used to convert the signal from the load cell to an SDI-12 output. A filtering algorithm is used to minimize the influence of evaporation, vibration (from wind), and temperature change on the precipitation signal.

Apogee SG-400 series precipitation gauges come partially assembled, facilitating easy transport and deployment. The gauge is housed in a lightweight, durable plastic shroud, with a powder-coated stainless steel inlet. Component parts include base plate, weighing assembly, collection bucket, and shroud/inlet.

Unit can be mounted to a wood post or metal pipe. Apogee recommends securing the post or pipe in a hole of at least 18 in/45 cm depth with cement. To provide accurate measurements, ensure the Cloudburst is level.