Frequently Asked Questions
Please note that many
questions are also answered in our
user manual.
I want to know how much rain has fallen in specific period of time. Will the RG-11 Rain Sensor easily do this for me?
Unfortunately, the RG-11 does not come with a readout, so it will not easily give the amount of rain fall over a time. The Rain Gauge has an output that "pulses" when a certain rain event -- set by the specific modes -- has occurred. It is up to the purchaser to interpret the data as they see fit.
We have received many calls and
inquiries from farmers wanting a simple, maintenance free rain gauge
that gives an easy to interpret readout. We have concluded that this
is not the product the farmers are looking for. The RG-11, in it's
current form, is mainly for system designers to design into other
products. Plus, the RG-11 is not wireless, which seems to be what
the farmers really want.
What is the accuracy of the RG-11 Rain Gauge?
The Hydreon Rain Gauge is not as accurate as a
properly maintained Tipping Bucket in ideal conditions.
We do not claim an accuracy specification for the RG-11
Rain Gauge. The RG-11 is very repeatable, and over a variety of
conditions will yield an average result that is reasonably close to that of a tipping bucket. But, for any given
rainstorm the result can be off by as much as 2:1 in either
direction. Even this is not an upper limit.
The strength of the RG-11 is that it works in many situations where a tipping bucket simply does not. That is, the Rain Sensor is vastly more accurate than a tipping bucket that has ceased to work properly due to dirt or mineral deposit or mechanical difficulty, or a tipping bucket in a mobile application that is constantly giving false indications due to motion. The RG-11 is more accurate for a small (but in some applications, meaningful) amount of rain, such as 0.01", that will simply not register in a tipping bucket.
This said, if you do not need the
ruggedness of the Hydreon Rain Gauge, and maintaining the
tipping bucket is not a problem, use a tipping bucket.
Does the RG-11 Rain Sensor work in direct sunlight?
Yes. The RG-11 rejects the
effects of sunlight using optics, filtering circuitry and software.
Normal fixed installations will be completely unaffected by
sunlight.
The RG-11 Rain Sensor can be, however,
affected by extremely bright, very rapidly changing sharp shadows.
Such shadows are generated, for example, by placing the RG-11 on
a moving vehicle and driving it under overhanging trees at, say 30
MPH. The effect is to decrease the sensitivity. The RG-11
compensates for this decrease in sensitivity in software, and the
output of the Rain Gauge is largely unaffected.
What material is the RG-11 made of?
The lens is made of UV stabalized
polycarbonate, the case is made of UV stabalized ABS, the screws are
stainless steel and the o-ring is silicone.
How do you set the RG-11 Rain Sensor for the different modes?
A DIP switch configures the
Rain Sensor to the different possible modes. Within each mode there
are as many as 16 possible further adjustments.
The O-ring doesn't fit properly, it's seems to be too small.
Try stretching it a before putting it into the groove.
This will help to expand the o-ring for a bit while you assemble the
RG-11 Rain Gauge. It is best to stretch it enough so it becomes
"too big" to fit in the groove. After the Rain Sensor has been in operation and assembled
for some time, the o-ring tends to stay in place when the RG-11
is disassembled. But if it falls out again, just stretch the o-ring
before assembly.
What kind of output does it have?
The output is relay interface, with
Common (COM), Normally Open (NO) and Normally Closed (NC)
connections.
Does the RG-11 Rain Gauge sense Condensation in Tipping Bucket and other modes?
Generally, the RG-11 will
sense condensation as if it were rainfall. The internal heater will
aid slightly in preventing condensation. Condensation, however,
seldom amounts to a significant accumulation of water.
My application is solar powered. Can I use the RG-11 Rain Sensor?
Yes. The normal current drain of the RG-11 is a reasonable
15 mA with no outputs on and no heater
enabled. But, the RG-11 also includes
modes that enable micro-power sleep mode when no rain is detected.
This drops the current consumption down to 1.5 mA for long periods
of time on dry days.
Does the RG-11 Rain Sensor still work when it is covered with water?
Yes. The Rain Sensor is looking for changes in the surface. This
can be a drop landing on one of the target regions, or rolling off
one of the target regions. When the Rain Sensor surface is covered
with water, additional water will continue to change the properties
of the surface. Some raindrops will cause an increase in
transmittance of the beams. Other raindrops will knock-off an existing
water droplet, and cause a decrease. The software
properly detects all such changes.
Does the RG-11 measure the size of the impinging rain drops?
Yes. Large drops that are a direct hit on one of the four target
regions are weighted more heavily in the algorithms than are small.
Direct hits count more than drops on the edge of the regions. Other
drops land on the top of the Rain Gauge before coalescing and running
over a target region. All of these events are statistically averaged
to form a reasonably accurate result.
Can I contact you if I have more questions?
Of Course! Email us at info@hydreon.com or call 877-5-SENSOR (877-573-6767). Email is generally a better way of communication for us and will be answered as soon as possible. But, if you need to call and we are in the office and not with other customers, your call will be answered by a live person.