You are here
Raingauge Field Calibration Device (FCD)
Field Calibration Device (FCD) has been designed in response to field Hydrologists’ requests for a device to check the calibration of Tipping Bucket Raingauges in the field. It is a light, portable device that allows field calibration tests.
How the FCD works
Using this instrument will save field time and money. The advantage of using a Field Calibration Device is that the Tipping Bucket Raingauges can remain fixed in their location and are therefore only out of service for a very short period of time.
The Field Calibration Device nozzle is unscrewed from the cylinder, which is in turn filled with water to the very top. The nozzle is then screwed back on the cylinder and placed through the holding plate which sits on the catch of any Tipping Bucket Raingauge. When the cap on the Field Calibration Device is closed, the air is entrapped in the cylinder. When the cap is removed a vacuum is created and the water is released down through the nozzle and into the Tipping Bucket Raingauge.
A preset volume (653ml) water will discharge through the Tipping Bucket Raingauge. This process is to be repeated a second time for an accurate calibration check. The number of tips can be manually counted or stored on the data logger for calibration check evidence and then checked with ‘‘Calibration Specifications’’ to confirm that the results come within the acceptable range.