260-2595 Rain Gauge Calibrator

The 260-2595 Rain Gauge Calibrator simplifies field verification and calibration procedures for tipping bucket rain gauges. It includes a 946-milliliter calibrated plastic bottle, a precision-machined water dispenser with four interchangeable orifices that provide the constant flow rates necessary for dynamic testing, and a 10-milliliter syringe that is useful for static tests. Calibration charts for all NovaLynx tipping bucket rain gauges are provided. Charts for other rain gauges are available.

For initial calibration adjustments, static calibration is recommended. This involves adjusting each bucket to tip for a measured volume of water. The 10-ml syringe allows for precise water volume measurements. Dynamic calibration involves adjusting both buckets to achieve the correct output count for a measured volume of water at a constant flow rate. It is recommended for minor adjustments and verification.

The four orifices provide a wide range of rainfall rates. To determine a gauge's error band, test its dynamic operation above and below the calibrated rate. Field verification is standardized by providing a controlled water volume at a constant flow rate. Verify that the gauge operates within the specified accuracy by comparing the output count to the calibration chart.