Hydreon RG-11 Optical Rain Gauge offers low-cost precipitation sensing

Hydreon RG-11 Rain Gauge

The Hydreon RG-11 optical rain gauge was born from the same technology that automatically triggers automobile windshield wipers.  The technologic overlap enabled the production of a low-cost optical precipitation sensor.

Hydreon engineers built the sensor due to public demand. “There wasn’t one single inquiry that got us to develop the RG-11, but after some time and so many inquiries, we decided it was time to develop a standalone rain sensor,” said Ben Gryskiewicz, Hydreon’s technical office manager.

The gauge is a compact, maintenance-free package that is easily mounted on a structure or pole to measure rain.  It uses beams of infrared light shining through a clear domed surface to measure precipitation.

The RG-11’s low cost makes it possible for science teachers to collect live data to teach the water cycle. It can keep an interested gardener in the know on how much precipitation quenched a prized pumpkin during a storm.  A watershed group with limited budget could use the gauge to collect qualitative precipitation measurements near a creek of interest.

The rain gauge has several selectable modes that can be activated with a series of switches. Different levels of sensitivity and functions can be applied in each mode.

For environmental applications, the RG-11 can act like a tipping bucket rain gauge with adjustable sensitivity.

Gryskiewicz said while the optical rain gauge does mimic a tipping bucket, it does not have the same accuracy in heavy rain events.  “The RG-11 works great in conjunction with a tipping bucket,” he said. “The measurement the RG-11 produces is great for qualitative rather than quantitative (measurements), meaning you’ll know when the precipitation is a light mist and not a heavy downpour.”

The RG-11 can also be a good failsafe against problems many tipping bucket users experience.  Stuck or clogged tipping buckets can leave researchers with a void of data.  Having a RG-11 nearby can provide an estimation of rainfall when all else fails.

Since the RG-11 is an optical sensor, it starts measuring precipitation as soon as water hits the sensor face. “A tipping bucket will typically miss the first couple of hundredths of an inch of rain as the collecting funnel fills,” said Gryskiewicz. “The RG-11 starts totalizing right away, and is thus more accurate than a tipping bucket for small rainfall accumulations.”

The RG-11 is programed to learn on the fly when set as a controller for other electrical devices. The mode prevents the sensor from reacting to slight changes in weather.

When set as a weather-dependent control device, the Hydreon RG-11 activates an internal relay to power a corresponding device. It can be wired to a user’s electrically powered skylight or windows to close when raining. Farmers can use the RG-11 to deactivate irrigation systems during rainy days. The RG-11 can also still be used for automatic wipers on large industrial vehicles like locomotives.

The Hydreon RG-11 optical rain gauge is a low cost option for those who need qualitative precipitation data or precipitation dependent controls on a budget.

The RG-11 retails for $59.