Hobo RXW-THC Series User manual

HOBOnet® RX Wireless Sensor Network
RXW Temperature/RH Sensor (RXW-THC-xxx) Manual
22242-F
This sensor measures temperature and RH and 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® web-based software. With
HOBOlink, you can monitor sensor readings, view graphs, set up alarms, download data, and
more.
Specifications
Sensor Temperature RH
Measurement Range -40°C to 75°C (-40°F to 167°F) 0–100% RH at -40° to 75°C (-40° to
167°F); exposure to conditions
below -20°C (-4°F) or above 95%
RH may temporarily increase the
maximum RH sensor error by an
additional 1%
Accuracy ±0.25°C from -40° to 0°C (±0.45°F
from -40° to 32°F)
±0.20°C from 0° to 70°C (±0.36°F
from 32° to 158°F)
±0.25°C from 70° to 75°C (±0.45°F
from 158° to 167°F)
±2.5% from 10% to 90% RH
typical to a maximum of ±3.5%
including hysteresis at 25°C
(77°F); below 10% and above
90% ±5% typical
Resolution 0.02°C (0.036°F) 0.01% RH
Drift <0.01°C (0.018°F) per year <1% per year typical
Response Time (typical, to
90% of change)
Without solar radiation shield: 3
minutes, 45 seconds in air moving
1 m/sec
With RS3-B solar radiation shield: 6
minutes, 30 seconds in air moving
1 m/sec
Without solar radiation shield: 15
seconds in air moving 1 m/sec
With RS3-B solar radiation shield:
30 seconds in air moving 1 m/sec
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-THC-900: 904–924 MHz
RXW-THC-868: 866.5 MHz
RXW-THC-921: 921 MHz
RXW-THC-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 3
Battery Type/
Power Source
Two AA 1.2V rechargeable NiMH batteries, powered by built-in solar
panel or two AA 1.5 V lithium batteries for operating conditions of -40° to
70°C (-40° to 158°F)
Battery Life With NiMH batteries: Typical 3–5 years when operated in the
temperature range -20° to 40°C (-4°F to 104°F) and positioned toward the
sun (see Deployment and Mounting), operation outside this range will
reduce the battery service life
With lithium batteries: 1 year, typical use
Memory 16 MB
RXW Temperature/
RH Sensor
Models:
•RXW-THC-900 (US)
•RXW-THC-868 (Europe)
•RXW-THC-921 (Taiwan)
•RXW-THC-922
(Australia/NZ)
Included Items:
•Cable ties
•Screws
Accessories:
•Solar radiation shield
(RS3-B)

RXW Temperature/RH Sensor (RXW-THC-xxx) Manual
1-800-LOGGERS 2 www.onsetcomp.com
Specifications (continued)
Dimensions Sensor: 45.97 x 11.43 x 10.16 mm (1.81 x 0.45 x 0.40 inches)
Cable length: 2 m (6.56 ft)
Mote: 16.2 x 8.59 x 4.14 cm (6.38 x 3.38 x 1.63 inches)
Weight Sensor and cable: 110 g (3.88 oz);
Mote: 223 g (7.87 oz)
Materials Sensor: Polyamide
Mote: PCPBT, silicone rubber seal
Environmental Rating Sensor: Weatherproof: 0 to 100% RH intermittent condensing
environments. For best results, the sensor should be mounted inside a
protective enclosure, such as a solar radiation shield.
Mote: IP67, NEMA 6
C
ompliance Marks RXW-THC-900: See last page
RXW-THC-868: The CE Marking identifies this product as
complying with all relevant directives in the European Union
(EU).
RXW-THC-921: See last page
RXW-THC-922: See last page
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 Deploying and Mounting).
Solar Panel: Position the solar panel towards the sun to charge
the mote batteries (see Deploying and Mounting).
Sensor Cable: This is the cable that 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
Deploying and Mounting).
Antenna: This is the built-in antenna for the radio
communications across the RX Wireless Sensor Network.
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).
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 an RX Wireless Sensor
Network to join (see Adding the Mote to the RX Wireless Sensor
Network).
LCD Screen: The mote is equipped with an LCD screen that
displays details about the current status. This 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.
Solar Panel
Button
Latch
USB Port
Battery Holder
LCD Screen
Mounting
Tab
Solar Panel Cable
Antenna
LEDs
Eyelet
Ground Wire
Port
Sensor Cable

RXW Temperature/RH Sensor (RXW-THC-xxx) Manual
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LCD Symbol Description
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 temperature and RH and
transmitting data. This requires accessing the station and the
mote at the same time so it is recommended that you complete
these steps before deploying the mote.
Important: If you are setting up a new 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:
1. If the LCD is blank on the station, press any button to wake
it up.
2. Press the Select button once (which shows the number of
smart sensors installed) and then press it again to switch to
the module with the manager (module 2 on RX2105 or
RX2106 stations).
3. Press the Search button (the magnifying glass). The
magnifying glass icon will blink while the station is in search
mode.
4. Open the mote door and install the batteries if you have not
already done so.
5. Press the button on the mote for 3 seconds. The signal
strength icon will flash and then cycle.
6. 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.
7. Press the Search button (the magnifying glass) on the
station to stop searching for motes.
Press this button to view the module
Press this button so the station is ready
to have motes join the network
Press this button for 3
seconds for the mote to
join the network
This signal strength icon
blinks while searching for
a network.
c.
Once a network is found,
the icon will stop flashing
and the bars will cycle from
left to right.
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 is
removed and the channel count
on the station LCD increases by
three (two for temperature/RH
and one for the mote battery).
a. b.

RXW Temperature/RH Sensor (RXW-THC-xxx) Manual
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1-800-LOGGERS (U.S. only)
If you added more than one more mote to the network, then
the total channel count on the station LCD for the manager
module will represent all measurement channels plus a battery
channel for each mote in the network.
Sensor measurements will be recorded at the logging interval
specified in HOBOlink, transmitted to the station, and uploaded
to HOBOlink at the next connection interval (readout). Use
HOBOlink to monitor mote status and health. If a mote is
temporarily offline, any logged data is saved until it is back
online. In addition, if a mote is offline for 30 minutes, the
station will automatically connect to HOBOlink and report the
mote as missing. Once the mote is back online, any logged data
will be uploaded the next time the station connects to
HOBOlink.
See the HOBOlink Help for details on how to change the logging
and connection intervals, view data, check mote status, add the
mote to a map, and more.
Deployment and Mounting
Mounting and Positioning the Mote
•Mount the mote to a mast or pipe using cable ties or affix
the mote to a wooden post or flat surface with screws.
Insert the cable ties or screws through the holes on the
mounting tabs.
•Consider using plastic poles such as PVC to mount the
mote as certain types of metal could decrease signal
strength.
•Make sure the mote remains in a vertical position once it
is placed in its deployment location for optimal network
communications.
•Make sure the mote door is closed, with both latches fully
locked to ensure a watertight seal.
•Consider using a 3/16 inch padlock to restrict access to the
mote. With the mote door closed, hook a padlock through
the eyelet on the right side of the door and lock it.
•Position the mote towards the sun, making sure the solar
panel is oriented so that it receives optimal sunlight
throughout each season. It may be necessary to
periodically adjust the mote position 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 mote is mounted a minimum of 1.8 m (6 ft)
from the ground or vegetation to help maximize distance
and signal strength.
•Place the mote so there is full line of sight with the next
mote. If there is an obstruction between two sensor
motes or between the sensor mote and the manager, then
use a repeater mounted on the obstruction. For example,
if there is a hill between the sensor mote and the
manager, place a repeater at the top of the hill between
the sensor mote and the manager.
•There should not be more than five motes in any direction
at their maximum transmission range from the manager.
Data logged by a wireless sensor must travel or “hop”
across the wireless network from one mote to the next
until it ultimately reaches the manager connected to the
station. To make sure the data can successfully travel
across the network, the mote should not be more than
five hops away from the manager.
•The HOBOnet Wireless Sensor Network can support up to
50 wireless sensors or 336 data channels per one HOBO
RX station.
•Use a #4-40 screw to attach a ground wire to the port on
the back of the mote if you are deploying the mote in a
location where lightning is a concern.
Sensor Mounting Guidelines
The solar radiation shield (RS3-B) is strongly recommended
when measuring outdoor air temperatures in direct sunlight.
Solar radiation can be a significant source of error in the
temperature and RH readings. Use the cable ties included with
the solar radiation shield (RS3-B) to secure the sensor in the
radiation shield as shown (see the Solar Radiation Shield
manual for additional assembly details).
•It is recommended that you mount the sensor vertically. If it
must be mounted horizontally, then make sure the vent on
the side of the sensor is vertical or facing down.
•Thermally isolate the sensor from the mounting surface to
ensure accurate air temperature and humidity readings.
•Protect the sensor from direct exposure to the weather. This
will prolong the sensor accuracy.
•If the sensor cable is left on the ground, it is recommended
that you use conduit to protect against animals, lawn
mowers, exposure to chemicals, etc.
•Refer to the station manual and Tripod Setup Guide at
www.onsetcomp.com/support/manuals for more
information regarding setting up stations.
Maintenance
The temperature/RH sensor is sensitive to dust, salts and other
airborne contamination. Periodically inspect the RH sensor. If
contamination is present on the protective cap, gently rinse it
with cool fresh water. If the sensor itself is contaminated, you
Press this button again to
stop searching for motes

RXW Temperature/RH Sensor (RXW-THC-xxx) Manual
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can rinse it with distilled water. Do not use hot water, organic
solvents, or detergents. Dry before use.
The mote is designed for outdoor use, but should be inspected
periodically. When inspecting the mote, do the following:
•Verify the mote is free of visible damage or cracks.
•Make sure the mote is clean. Wipe off any dust or grime
with a damp cloth.
•Wipe off any water before opening the mote.
•Make sure the interior seal is intact and the latches are
fully locked when the mote door is closed.
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 click your
station name.
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.
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.
Make sure
solar panel
cable is
installed
when using
rechargeable
batteries