Hobo HOBOnet RXW-WL-900 User manual

HOBOnet® Wireless Sensor Network
HOBOnet Water Level Sensor Interface User Guide
28084-B
This sensor interface, which is compatible with the MX2001 suite of sensors, monitors changing
water levels in a wide range of applications, including streams, lakes, wetlands, tidal areas, and
groundwater. It is designed to work with the HOBOnet (HOBO® RX) Wireless Sensor Network in
which data is transmitted wirelessly from the sensor mote across the network to the station and
then uploaded to HOBOlink® cloud software. With HOBOlink, you can monitor sensor readings,
view graphs, set up alarms, download data, and more.
Specifications
W
ireless Mote
O
perating Temperature
Range
-25° to 60°C (-13° to 140°F) with rechargeable batteries
-40° to 70°C (-40° to 158°F) with lithium batteries
Radio Power 12.6 mW (+11 dBm) non-adjustable
Transmission Range Reliable connection to 457.2 m (1,500 ft.) line of sight at 1.8 m (6 ft.) high
Reliable connection to 609.6 m (2,000 ft.) line of sight at 3 m (10 ft.) high
Wireless Data Standard IEEE 802.15.4
Radio Operating
Frequencies
RXW-WL-900: 904–924 MHz
RXW-WL-868: 866.5 MHz
RXW-WL-921: 921 MHz
RXW-WL-922: 916–924 MHz
Modulation Employed OQPSK (Offset Quadrature Phase Shift Keying)
Data Rate Up to 250 kbps, non-adjustable
Duty Cycle <1%
Maximum Number of
Motes
Up to 50 wireless sensors or 336 data channels per one HOBO RX station
Logging Rate 1 minute to 18 hours
Number of Data Channels 4 (Water Level, Differential Pressure, Water Temperature, Barometric
Pressure)
Battery Type/
Power Source
Two AA 1.2V rechargeable NiMH batteries, powered by built-in solar
panel or two AA 1.5V non-rechargeable lithium batteries for operating
conditions of -40 to 70°C (-40 to 158°F)
Battery Life With NiMH batteries: Typical 3–5 years when used in the temperature
range -20° to 40°C (-4°F to 104°F) and positioned toward the sun (see
Mounting and Positioning the Mote); using the batteries outside this range
reduces the battery life.
With non-rechargeable lithium batteries: 1 year, typical use.
Memory 16 MB
Dimensions Interface Connector Diameter: 25.4 mm (1 inch)
Cable length: 1.83 m (6 ft)
Mote: 16.2 x 8.59 x 4.14 cm (6.38 x 3.38 x 1.63 inches)
Weight 229 g (8.08 oz)
Materials Sensor: Polycarbonate housing encasing epoxy sealed circuit board
Cable: Polyurethane
Mote: PCPBT, silicone rubber seal
Environmental Rating Mote: IP67, NEMA 6
Compliance Marks RXW-WL-900: See last page.
RXW-WL-868: The CE Marking identifies this product as
complying with all relevant directives in the European Union
(EU).
RXW-WL-921: See last page.
RXW-WL-922: See last page.
RXW Water Level Sensor
Models:
•RXW-WL-900 (US)
RXW-WL-868 (Europe)
RXW-WL-921 (Taiwan)
RXW-WL-922 (Australia/NZ)
Included Items:
•Cable ties
•Screws

HOBOnet Water Level Sensor Interface User Guide
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Water Level Sensor
Pressure (Absolute) and Water Level Measurements MX2001-01-SS-S and MX2001-01-Ti-S
Operation Range 0 to 207 kPa (0 to 30 psia); approximately 0 to 9 m (0 to 30 ft) of water depth at sea level, or 0 to 12 m (0 to 40 ft) of water
at 3,000 m (10,000 ft) of altitude
Factory Calibrated
Range
69 to 207 kPa (10 to 30 psia), 0° to 40°C (32° to 104°F)
Burst Pressure 310 kPa (45 psia) or 18 m (60 ft) depth
Water Level
Accuracy*
Typical error: ±0.05% FS, 0.5 cm (0.015 ft) water
Maximum error: ±0.1% FS, 1.0 cm (0.03 ft) water
Raw Pressure
Accuracy**
±0.3% FS, 0.62 kPa (0.09 psi) maximum error
Resolution <0.02 kPa (0.003 psi), 0.21 cm (0.007 ft) water
Pressure Response
Time (90%)***
<1 second at a stable temperature
Pressure (Absolute) and Water Level Measurements MX2001-02-SS-S
Operation Range 0 to 400 kPa (0 to 58 psia); approximately 0 to 30.6 m (0 to 100 ft) of water depth at sea level, or 0 to 33.6 m (0 to 111 ft)
of water at 3,000 m (10,000 ft) of altitude
Factory Calibrated
Range
69 to 400 kPa (10 to 58 psia), 0° to 40°C (32° to 104°F)
Burst Pressure 500 kPa (72.5 psia) or 40.8 m (134 ft) depth
Water Level
Accuracy*
Typical error: ±0.05% FS, 1.5 cm (0.05 ft) water
Maximum error: ±0.1% FS, 3.0 cm (0.1 ft) water
Raw Pressure
Accuracy**
±0.3% FS, 1.20 kPa (0.17 psi) maximum error
Resolution <0.04 kPa (0.006 psi), 0.41 cm (0.013 ft) water
Pressure Response
Time (90%)***
<1 second at a stable temperature
Pressure (Absolute) and Water Level Measurements MX2001-03-SS-S
Operation Range 0 to 850 kPa (0 to 123.3 psia); approximately 0 to 76.5 m (0 to 251 ft) of water depth at sea level, or 0 to 79.5 m (0 to 262
ft) of water at 3,000 m (10,000 ft) of altitude
Factory Calibrated
Range
69 to 850 kPa (10 to 123.3 psia), 0° to 40°C (32° to 104°F)
Burst Pressure 1,200 kPa (174 psia) or 112 m (368 ft) depth
Water Level
Accuracy*
Typical error: ±0.05% FS, 3.8 cm (0.125 ft) water
Maximum error: ±0.1% FS, 7.6 cm (0.25 ft) water
Raw Pressure
Accuracy**
±0.3% FS, 2.55 kPa (0.37 psi) maximum error
Resolution <0.085 kPa (0.012 psi), 0.87 cm (0.028 ft) water
Pressure Response
Time (90%)***
<1 second at a stable temperature
Pressure (Absolute) and Water Level Measurements MX2001-04-SS-S and MX2001-04-Ti-S
Operation Range 0 to 145 kPa (0 to 21 psia); approximately 0 to 4 m (0 to 13 ft) of water depth at sea level, or 0 to 7 m (0 to 23 ft) of water
at 3,000 m (10,000 ft) of altitude
Factory Calibrated
Range
69 to 145 kPa (10 to 21 psia), 0° to 40°C (32° to 104°F)
Burst Pressure 310 kPa (45 psia) or 18 m (60 ft) depth
Water Level
Accuracy*
Typical error: ±0.075% FS, 0.3 cm (0.01 ft) water
Maximum error: ±0.15% FS, 0.6 cm (0.02 ft) water
Raw Pressure
Accuracy**
±0.3% FS, 0.43 kPa (0.063 psi) maximum error
Resolution <0.014 kPa (0.002 psi), 0.14 cm (0.005 ft) water
Pressure Response
Time (90%)***
<1 second at a stable temperature

HOBOnet Water Level Sensor Interface User Guide
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Barometric Pressure (RXW-WL-xxx)
Operation Range 66 to 107 kPa (9.57 to 15.52 psia)
Temperature
Calibrated Range
-20 to 50°C (-4 to 122°F)
Accuracy ±0.2 kPa (±0.029 psi) over full temperature range at fixed pressure; maximum error ±0.5% FS
Water Level Accuracy* Typical error: ±0.075% FS, 0.3 cm (0.01 ft) water
Maximum error: ±0.15% FS, 0.6 cm (0.02 ft) water
Resolution <0.01 kPa (0.0015 psi)
Response Time <1 second at stable temperature
Stability (Drift) <0.01 kPa (0.0015 psi) per year
T
emperature Measurements (All Sensor End Models MX2001-0x-SS-S and MX2001-0x-Ti-S)
Operation Range -20° to 50°C (-4° to 122°F)
Accuracy ±0.44°C from 0° to 50°C (±0.79°F from 32° to 122°F), see Plot A
Resolution 0.1°C at 25°C (0.18°F at 77°F), see Plot A
Response Time (90%) 5 minutes in water (typical)
Stability (Drift) 0.1°C (0.18°F) per year
* Water Level Accuracy: With accurate reference water level measurement, known water density,
and a stable temperature environment. System Water Level Accuracy equals the sum of the
Barometric Water Level Accuracy plus the selected sensor end Water Level Accuracy.
** Raw Pressure Accuracy: Absolute pressure sensor accuracy includes all sensor drift, temperature,
and hysteresis-induced errors.
*** Changes in Temperature: Allow 20 minutes in water to achieve full temperature compensation of
the pressure sensor. There can be up to 0.5% of additional error due to rapid temperature
changes. Measurement accuracy also depends on temperature response time.
Mote Components and Operation
Sensor Mote Closed, Front Sensor Mote Closed, Back
Sensor Mote Opened
Mounting Tab: Use the tabs at the top and bottom of the mote
to mount it (see Mounting and Positioning the Mote).
Solar Panel: Position the solar panel towards the sun to charge
the batteries (see Mounting and Positioning the Mote).
Sensor Cable: This cable connects the mote to the sensor.
Eyelet: Use this eyelet to attach a 3/16 inch padlock to the
mote for security.
Latch: Use the two latches to open and close the mote door.
Ground Wire Port: Use this port to connect a ground wire (see
Mounting and Positioning the Mote).
Antenna: This built-in antenna provides radio communications
across the RX Wireless Sensor Network.
Mounting
Tab
Solar Panel Latch
Eyelet
Ground Wire
Port
Sensor Cable
Solar Panel Cable
Button
USB Port
Battery Holder
LCD Screen
Antenna
LEDs
Calibration Connection Pins
Vent hole

HOBOnet Water Level Sensor Interface User Guide
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LEDs: There are two LEDs to the left of the LCD screen. The
green LED blinks during the process of joining a network,
blinking quickly while the mote searches for a network and
then slowly as the mote registers with the network. Once the
network registration process is complete, the blue LED blinks at
4 seconds to indicate normal operation. If the mote is not
currently part of a network, the blue LED will be off. If the blue
LED is on and not blinking, there is a problem with the mote.
Contact Onset Technical Support.
Solar Panel Cable: This cable connects the built-in solar panel
to the mote circuitry.
Battery Holder: The location where the batteries are installed
as shown (see Battery Information).
Calibration Connection Pins: Use these pins to connect a
programming tool. See Performing a Soil-Specific Calibration for
details.
USB Port: Use this port to connect to the mote to a computer
via USB cable if you need to update the firmware (see Updating
Mote Firmware).
Button: Push this button for 1 second to illuminate the LCD or 3
seconds for the mote to search for a HOBOnet Wireless Sensor
Network to join (see Adding the Mote to the HOBOnet Wireless
Sensor Network).
LCD Screen: The mote is equipped with an LCD screen that
displays details about the current status. The following example
shows all symbols illuminated on the LCD screen followed by
definitions of each symbol in the table.
LCD Symbol Description
The battery indicator shows the approximate battery
charge remaining.
This is a signal strength indicator. The more bars, the
stronger the signal between motes. If there is no x
icon next to the signal strength indicator, then the
mote is part of a HOBOnet Wireless Sensor Network.
An empty signal strength icon plus the x icon
indicates that the mote is not currently part of a
network. See Adding the Mote to the HOBOnet
Wireless Sensor Network for details on how to add a
mote to the network.
When the mote is in the process of joining a
network, the signal strength icon will blink and then
the bars in the icon will cycle from left to right. The x
icon will blink during the last step in the network
registration process (see Adding the Mote to the
HOBOnet Wireless Sensor Network for details).
This indicates a problem with the sensor itself (the
mote is operational). Check the sensor and make any
adjustments to it as needed. Contact Onset
Technical Support if the problem persists.
Adding the Mote to the HOBOnet Wireless Sensor
Network
The mote must join a HOBOnet Wireless Sensor Network
before it can begin measuring water level and transmitting
data. This requires that you have access to the RX Station and
the mote at the same time; we recommend that you complete
these steps before deploying the mote.
Important: If you are setting up a new RX Station, follow the
instructions in the station quick start before setting up this
mote (go to www.onsetcomp.com/support/manuals/24380-
man-rx2105-rx2106-qsg for RX2105 and RX2106 stations or go
to www.onsetcomp.com/support/manuals/18254-MAN-QSG-
RX3000 for RX3000 stations).
To add a mote to the network using the RX Station:
1. If the LCD is blank on the station, press any button to wake
it up.
2. Press the Select button once (the number of smart sensors
is displayed above Channels). Press Select again to switch to
the module with the manager.
3. Press the Search button (the magnifying glass). The
magnifying glass icon blinks while the station is searching.
4. Connect the interface connector to the sensor with the
direct-read cable in between as shown here. The end of the
cable with the longer housing connects to the interface
connector as shown below.
5. Open the mote door and install the batteries if you have not
already done so.
Press this button to view the module
Press this button to search for motes to
join the network
Interface
Connector
Plug this part of the cable
with the longer housing into
the interface connector and
screw it to hand tighten.
Plug this part of the cable with the
shorter housing into the sensor
end and screw it to hand tighten.
Sensor end

HOBOnet Water Level Sensor Interface User Guide
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6. Press the button on the mote for 3 seconds. The signal
strength icon flashes and then cycles.
7. Watch the LCD on the mote.
The green LED blinks quickly while the mote searches for a
network to join and then blinks slowly while it completes
the network registration. Once the mote has finished
joining the network, the green LED turns off and the blue
LED then blinks indefinitely while the mote is part of the
network.
Note: If the mote cannot find the network or has trouble
remaining connected during this process, make sure the
mote is in a vertical, upright position and within range of
the station.
8. Press the Search button (the magnifying glass) on the
station to stop searching for motes.
If you added more than one more mote to the network, then
the total channel count on the station LCD for the manager
module represents all measurement channels plus a battery
channel for each mote in the network.
Sensor measurements are recorded at the logging interval
specified in HOBOlink, transmitted to the station, and uploaded
to HOBOlink at the next connection interval (readout).
Mounting and Positioning the Sensor Node
•Position the sensor node towards the sun, making sure the
solar panel is oriented so that it receives optimal sunlight
throughout each season. You may need to periodically
adjust the position of the sensor node as the path of the
sunlight changes throughout the year or if tree and leaf
growth alters the amount of sunlight reaching the solar
panel.
•Make sure the sensor node is mounted a minimum of 1.8 m
(6 feet) from the ground or vegetation to help maximize
distance and signal strength.
•Consider using plastic poles such as PVC to mount the
sensor node as certain types of metal could decrease the
signal strength.
•Place the sensor node so there is full line of sight with the
next sensor node. Use a repeater if there is an obstruction
between sensor nodes.
•There should not be more than five sensor nodes in any
direction from a repeater or the manager. Data from sensor
nodes travels or “hops” across the network and may not
reach the station if the sensor node is more than five hops
away.
Deploying the Water Level Sensor
Warning: Do not suspend anything from the 6-foot
cable. The 6-foot cable is not designed to support the
weight of the direct-read cable and sensor.
Press this button again to
stop searching for motes.
Press this button for 3
seconds to have the mote
join the network.
This signal strength icon
blinks while the mote
searches for a network.
Once the mote finds a
network, the icon stops
flashing. The bars cycle
from left to right.
c. d.
This network connection
“x” icon blinks while the
mote completes the
registration process,
which may take up to
five minutes.
Once the mote has finished
joining the network, the “x”
icon disappears and the channel
count on the station LCD
increases by the total channel
count for that sensor model.
a. b.
6-foot cable

HOBOnet Water Level Sensor Interface User Guide
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Suspending the direct-read cable and water level sensor
•Option 1 (preferred): Using the long direct-read cable
(CABLE-DR-xxx) and a compatible well-cap
•Option 2: Using the mounting hole on the endcap
The endcap contains a loop that allows you to use a
carabiner (rated to 50 lbs. or greater) or some other
reliable method to suspend the interface connector.
Water Level Scaling in HOBOlink
The following sections provide information on how to measure
the reference water level and account for water density.
Scenario 1: Setting a Reference Water Level
1. Deploy the water level sensor in water and secure it
in position (for example, hang it in a well).
2. Make sure your RX Station is logging and connecting
fast enough for you to see the current water depth
readings. (Press connect on the RX Station to see the
latest logged value).
3. Enable Scaling for the HOBOnet water level sensor. In
HOBOlink:
a. Select Devices, RX Devices, then select your station.
b. Select the wrench at the top of the page and select
Module/Sensor Configuration from the menu.
c. Select Water Level for the appropriate sensor. On
the right side of the page, ensure that Enable Scaling
is selected.
4. Enter the scaling values:
a. Enter the Scaled Units: for example meters or feet.
This should match the units shown in Latest Value,
or you will need to adjust the multiplier to convert.
b. Enter the multiplier in the Multiplier field.
Multiplier*
Fresh water 1
Brackish water 0.99
Salt water 0.9765
c. Enter 0 in the Offset field for now.
d. Enter the Scaled Measurement Type, for example
“Pond Water Level”.
5. Click save and note the Latest Value.
6. Take a reference water level measurement.
•Note this as a negative number if the water level
surface is below the reference point, such as
groundwater level referenced to the top of the
well (Figure 1).
•Note this as a positive number if the water level
surface is above the reference point, such as the
bottom of the stream or the zero on a staff
gauge (Figure 2).
7. Calculate the offset, which is equal to the reference
water level reading (from step 6) minus the current
water depth reading (from HOBOlink in step 5).
8. Enter the calculated offset in the Offset field.
9. Click save.
10. Verify latest value matches the correct water level.
Route the direct-read cable through the
posts of the well-cap to secure the cable.
CABLE-DR-xxx
WELL-CAP-02
(shown as an example)
Note: If you choose this option, the interface
connector is outside of the well.
Mounting Hole
Example using a carabiner
with WELL-CAP-02

HOBOnet Water Level Sensor Interface User Guide
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Scenario 2: Measuring Water Depth (Figure 3)
1. Ensure the water level sensor is in the air.
2. Make sure your RX Station is logging and connecting
fast enough for you to see the current water depth
readings. (Press connect on the RX Station to see the
latest logged value).
3. Enable Scaling for the HOBOnet water level sensor. In
HOBOlink:
a. Select Devices, RX Devices, then select your
station.
b. Select the wrench at the top of the page
and select Module/Sensor Configuration
from the menu.
c. Select Water Level for the appropriate
sensor. On the right side of the page,
ensure that Enable Scaling is selected.
(Refer to the screen shot in step 3 of the
previous section.)
4. Enter the scaling values:
a. Enter the Scaled Units: for example meters
or feet. This should match the units shown
in Latest Value, or you will need to adjust
the multiplier to convert.
b. Enter the multiplier in the Multiplier field.
Multiplier*
Fresh water 1
Brackish water 0.99
Salt water 0.9765
c. Enter 0 in the Offset field for now.
d. Enter the Scaled Measurement Type, for
example “Pond Water Level”.
5. Click save and note the Latest Value.
6. Calculate the offset, which is equal to zero minus the
current water depth reading (from step 5).
7. Enter the calculated offset in the Offset field.
8. Click save. Latest value should be zero.
9. Deploy the water level sensor in water and secure it
in position (for example, hang it in a well).
Figure 1: Water level is below reference point
Figure 2: Water level is above reference point
Figure 3: Water level is above pressure sensor
General Guidelines
•The absolute pressure sensor in the water level sensor is
temperature compensated over the range of 0° to 40°C
(32° to 104°F). The barometric pressure sensor is
temperature compensated over the range of -20° to 50°C
(-4° to 122°F). To obtain the highest level of accuracy,
both the sensor and station should be allowed to come
to full temperature equilibrium (approximately 20
minutes) before the reference level is entered in
HOBOlink as described in Setting up the Station.
•Sudden temperature changes should be avoided.
•When deploying the water level sensor in a well, make
sure the well is vented to the atmosphere. Typically, a
small hole can be drilled in the side of the well cap to
ensure that the pressure inside and outside the well is at
equilibrium. Use the Onset well cap (WELL-CAP-02) if it is
a 5 cm (2 inch) well. Otherwise, you will need to find
another method of attaching the cable at the top of your
well so that the sensor stays in position. The sensor cable
includes a Kevlar® strength member so it can support the
weight of the sensor and its cable. You can attach a
clamp around the cable, such as a hose clamp, but be
careful not to damage the cable.
•There is a vent for the barometric sensor on the back of
the mote. This vent must not collect water or it will block
proper barometric pressure readings. The best way to
avoid water collecting is to mount the station vertically.
•The sensor face located in the nose cone of the sensor
end needs to be in the water to measure water level.
*The Multiplier represents the density of the water, which is a function of its salinity. This is equal to 1 divided by the true density of the water in g/cm3
(e.g., 1/1.025 for typical salt water).

HOBOnet Water Level Sensor Interface User Guide
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•Any change in length of the sensor cable will result in a 1-
to-1 corresponding error in the depth measurement.
Always pull-test a cable prior to deploying a sensor in a
well to make sure it does not stretch.
•If you are deploying the sensor in a lake, river, or stream,
you must first build a stilling well to protect it and the
cable. A simple stilling well can be constructed with PVC
or ABS pipe. A properly constructed stilling well holds the
sensor in position and protects the sensor from currents,
wave action, and debris. Suspend the sensor in the
stilling well so it is always underwater, but not on the
bottom to be buried by silt.
For more information, see the Technical Application Note
for How to Build a Stilling Well at:
https://www.onsetcomp.com/resources/tech-notes/how-
to-build-stilling-well
•To prevent the sensor from moving in currents and to
ensure the support cable is kept straight during
deployment, you may need to add a weight to the
suspension cable just above the sensor or hang a weight
below the sensor. In some cases, you may need to both
add a weight and use a stilling well.
•Be very careful not to exceed the burst pressure for the
sensor. The pressure sensor will burst if the maximum
depth is exceeded (see Specifications). The sensor should
be positioned at a depth where it will remain in the
water for the duration of the deployment, but not
exceed the rated bursting depth.
•If the cable is too long, loop the cable and secure the
cable with multiple zip ties to ensure the loop does not
slip. The looped cable should be tight enough that the
cable can be easily pulled out of the well if necessary, but
it must not bend the cable any tighter than a 1.25 cm (0.5
inch) radius to prevent damage to the cable.
Updating Mote Firmware
If a new firmware version is available for the mote, use
HOBOlink to download the file to your computer.
1. In HOBOlink, go to Devices, then RX Devices, and select the
name of your station.
2. On the station page, click Overview and scroll down to
Device Information.
3. Click the Wireless tab. This icon appears next to the
mote if there is a new version of firmware available.
4. Click the firmware upgrade link. Click Download and
save the firmware .bin file to your computer.
5. Connect the mote to the computer with a USB cable (open
the mote door and use the USB port to the right of the
LCD). The blue LED is illuminated while connected.
6. The mote appears as a new storage device in the
computer’s file storage manager. Copy the downloaded
firmware file to the new storage device (the mote). The
blue LED will blink slowly while the file is copying.
7. After the file is copied to the mote, the LED will stop
blinking and remain a steady blue. Eject the storage device
from the computer and disconnect the cable from the
mote. The firmware installation process will begin
automatically on the mote. The blue LED will blink rapidly
while the firmware is installed. Once the firmware
installation is complete, the LCD symbols return and the
mote will automatically rejoin the network.
Notes:
•Mac® users: A message may appear indicating the disk
has not ejected properly when disconnecting the mote
from the computer. The mote is operational and you can
ignore the message.
•If the blue LED turns off abruptly while copying the file or
installing the firmware, a problem has occurred. Contact
Onset Technical Support for help.
Battery Information
The mote uses two 1.2 V rechargeable NiMH batteries, charged
by the built-in solar panel. The quality and quantity of solar
light can affect whether the battery is sufficiently charged to
last through the night and cloudy periods. Make sure the mote
is placed in a location that will receive several hours of sunlight
each day. If the mote does not receive enough sunlight to
recharge the batteries, the battery life is estimated at 3–4
months. When batteries are regularly recharged, expected
battery life is estimated at 3–5 years. Battery life varies based
on the ambient temperature where the mote is deployed, the
logging interval, the number of tripped alarms, and other
factors. Deployments in extremely cold or hot temperatures
can impact battery life. Estimates are not guaranteed due to
uncertainties in initial battery conditions and operating
environment.
Mote operation will stop when battery voltage drops to 1.8 V.
Mote operation will return if the battery recharges to 2.3 V. If
the batteries are unable to be recharged, replace them with
fresh rechargeable batteries. Note: if you install used
rechargeable batteries that together are less than 2.3 V, the
mote will not resume operation.
Make sure the
sensor face
(represented by
dashed lines in
this diagram) is in
the water to
measure water
level
10.0 mm (0.39 in.)

HOBOnet Water Level Sensor Interface User Guide
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To replace rechargeable batteries:
1. Open the mote door.
2. Remove the old batteries and install fresh ones observing
polarity.
3. Make sure the solar panel cable is plugged in.
The mote contacts the network once the new batteries are
installed. The green LED blinks during this process while the
bars in the signal strength indicator on the LCD cycle from left
to right and then the x icon blinks. Once this process is
complete, the x icon is removed, the green LED stops blinking,
and the blue LED begins blinking instead.
Lithium Batteries
You can use two 1.5 V lithium batteries (HWSB-LI) for operation
at the extreme ends of the mote operating range. Lithium
battery life is an estimated at 1 year, but varies based on the
ambient temperature where the mote is deployed, the logging
interval, the number of tripped alarms, and other factors.
Estimates are not guaranteed due to uncertainties in initial
battery conditions and operating environment. When using
lithium batteries, you must disconnect the solar panel cable
because the batteries will not be recharged.
To install lithium batteries:
1. Open the mote door.
2. Remove any old batteries and install the new ones
observing polarity.
3. Push in the side tab of the solar panel cable connector and
pull the connector out of the cable port.
4. Place the connector in the slot on the inside of the mote
door. Make sure the solar panel cables are tucked inside the
door so that they do not interfere with the interior seal
when the mote is closed.
The mote contacts the network once the new batteries are
installed. The green LED blinks quickly while the mote searches
for a network to join and then blinks slowly while it completes
the network registration. Once the mote has finished joining
the network, the green LED turns off and the blue LED then
blinks indefinitely while the mote is part of the network.
WARNING: Do not cut open, incinerate, heat above 85°C
(185°F), or recharge the lithium batteries. The batteries may
explode if the mote is exposed to extreme heat or conditions
that could damage or destroy the battery cases. Do not mix
battery types, either by chemistry or age; batteries may rupture
or explode. Do not dispose of the logger or batteries in fire. Do
not expose the contents of the batteries to water. Dispose of
the batteries according to local regulations for lithium
batteries.
Store the solar
panel connector
here when using
lithium batteries
Make sure
solar panel
cable is
installed
when using
rechargeable
batteries

HOBOnet Water Level Sensor Interface User Guide
U.S. and International Sales: 1-508-759-9500
www.onsetcomp.com/contact/support
© 2020–2023 Onset Computer Corporation. All rights reserved. Onset, HOBO, HOBOnet, and HOBOlink are registered
trademarks of Onset Computer Corporation. All other trademarks are the property of their respective companies.
28084-B
Federal Communication Commission Interference Statement
This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to Part 15 of the FCC Rules. These limits are designed to provide
reasonable protection against harmful interference in a residential installation. This equipment generates, uses, and can radiate radio frequency energy and, if not installed and
used in accordance with the instructions, may cause harmful interference to radio communications. However, there is no guarantee that interference will not occur in a
particular installation. If this equipment does cause harmful interference to radio or television reception, which can be determined by turning the equipment off and on, the user
is encouraged to try to correct the interference by one of the following measures:
•Reorient or relocate the receiving antenna
•Increase the separation between the equipment and receiver
•Connect the equipment into an outlet on a circuit different from that to which the receiver is connected
•Consult the dealer or an experienced radio/TV technician for help
This device complies with Part 15 of the FCC Rules. Operation is subject to the following two conditions: (1) This device may not cause harmful interference, and (2) this device
must accept any interference received, including interference that may cause undesired operation.
FCC Caution: Any changes or modifications not expressly approved by the party responsible for compliance could void the user's authority to operate this equipment.
Industry Canada Statements
This device complies with Industry Canada license-exempt RSS standard(s). Operation is subject to the following two conditions: (1) this device may not cause interference, and
(2) this device must accept any interference, including interference that may cause undesired operation of the device.
Avis de conformité pour l’Industrie Canada
Le présent appareil est conforme aux CNR d'Industrie Canada applicables aux appareils radio exempts de licence. L'exploitation est autorisée aux deux conditions suivantes : (1)
l'appareil ne doit pas produire de brouillage, et (2) l'appareil doit accepter tout brouillage radioélectrique subi, même si le brouillage est susceptible d'en compromettre le
fonctionnement.
To comply with FCC and Industry Canada RF radiation exposure limits for general population, the logger must be installed to provide a separation distance of at least 20cm from
all persons and must not be co-located or operating in conjunction with any other antenna or transmitter.
NCC Statement
經型式認證合格之低功率射頻電機，非經許可，公司、商號或使用者均不得擅自變更頻率、加大功率或變更原設計之特性及功能。
低功率射頻電機之使用不得影響飛航安全及干擾合法通信；經發現有干擾現象時，應立即停用，並改善至無干擾時方得繼續使用。前項合法通信，指依電信法規定作
業之無線電通信。低功率射頻電機須忍受合法通信或工業、科學及醫療用電波輻射性電機設備之干擾。
Translation:
Article 12
Without permission granted by the NCC, any company, enterprise, or user is not allowed to change frequency, enhance transmitting power or alter original characteristic as well
as performance to an approved low power radio-frequency device.
Article 14
The low power radio-frequency devices shall not influence aircraft security and interfere with legal communications. If found, the user shall cease operating immediately until no
interference is achieved. The said legal communications means radio communications is operated in compliance with the Telecommunications Act. The low power radio-
frequency devices must be susceptible with the interference from legal communications or ISM radio wave radiated devices.