Rain Level Sensor
RANLWE01
T
his rain sensor
measures the
amount of rain at the location of
the sensor
in ml within a 15 minute interval and
transmits it via LoRaWAN. In case of
heavy rain
(more than 15 l/h), an alarm
message is issued.
The device is powered by two AAA batteries. The
supplied high-quality VARTA, batteries allow a
runtime of over 8 years.
Setup
Please register the device with its three keys with
your LoRaWAN server before commissioning. You
will find the Device EUI printed on the device. Enter
this key on https://aqua-scope.com/lora to get
the missing keys.
Open the sensor by turning the housing
counterclockwise against the housing base. Now
remove the communication module as shown in
Figure 2.
After inserting the batteries, the LED next to the
button flashes red/green (see Figure 1), indicating
an active JOIN process. This is terminated with a
successful JOIN on the network or after 20
seconds. The LED will indicate whether the JOIN
process was successful by glowing red or green. If
no network connection has been established, the
device will switch to internal Aqua-Scope
communication mode and can communicate
directly with Aqua-Scope monitor devices even
without a LoRaWAN network. The LoRaWAN JOIN
process can be restarted using the button and a
paper clip.
After plugging in the communication mode, you
can simulate rain by moving the rocker and thus
test whether and how such rain is reported by the
sensor. Please note that the flat side of the
communication module must be on the side of the
water rocker.
Functions
Now place the sensor on a horizontal surface. A
sight glass in the bottom of the housing will help
with alignment.
When rain falls, the sensor will transmit the
corresponding amount of rain every15 minutes.
The minimum resolution of the sensor is 0.5 mm
water column. Please note that this amount of rain
can only be measured exactly at the sensor.
Already a few meters away from it, other rain
amounts can occur. In case of heavy rain, a
corresponding alarm is sent within approx. 2
minutes, which is deleted again when the rain
intensity falls below the threshold. The threshold
value for start rain can be defined in configuration
parameter 3. It is preset at the factory to 15
liters/hour.
If no rain is measured within a 15-minute interval,
no radio transmission will take place to save the
battery. The measuring interval can be freely
defined via configuration parameter 1. Even
without rain, the sensor will report regularly and
transmit its uptime. By default, this wake-up
interval is set to 6 hours and can be defined with
configuration parameter 2.
In addition to the heavy rain alarm, the device
sends an alarm when the battery is almost
exhausted. In this case, however, you still have
several months to replace the batteries.
General Information reg. metering of rain
Rain is measured either in mm water column above a point or
as a quantity in liters on an area of 1 square meter. 1
liter/square meter corresponds to a water column of 1 mm. In
the case of snowfall, this 1 mm water column corresponds to a
snow depth of about 1 cm of snow.
Professional meteorological institutes use standardized rain
gauges with an opening of at least 200 mm (specified in
Chinese national standard GB/T 21978.2-2014 "Instrument for
precipitation observation. Part 2: Tipping bucket rainfall
sensor"). In contrast, this sensor has an aperture of only 130
mm, which allows sufficient measurement accuracy and still
does not take up too much space.
Technical Data
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Platform: STM32WLE5CCU6
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LoRaWAN
§
Frequency: EU868
§
Join process: OTAA
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Class A
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Standard: LoRaWAN 1.0.3
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Range: > 10km (TX 22 dB).
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Temp. range: -40 ... 85 deg C
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Water protection: IP 55
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Dimension: 132x132x139 mm
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Dims. packed: 140x140x150 mm
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Weight: 219 gr.