Hobo U12-011 User manual

HOBO®U12 Temp/RH
Data Logger
(Part # U12-011)
© 2009–2012 Onset Computer Corporation
Inside this package:
HOBO U12 Temp/RH Data
Logger
Mounting kit with magnet,
hook and loop tape, tie-wrap
mount, tie wrap, and two
screws.
Doc # 13127-B, MAN-U12011
Onset Computer Corporation
Thank you for purchasing a HOBO data
logger. With proper care, it will give you
years of accurate and reliable measurements.
The HOBO U12 Temperature/Relative
Humidity Data Logger is a two-channel
logger with 12-bit resolution and can record
up to 43,000 measurements or events. The
logger uses a direct USB interface for
launching and data readout by a computer.
An Onset software starter kit is required for
logger operation. Visit www.onsetcomp.com
for compatible software.
Specifications
Measurement
range Temperature: -20° to 70°C (-4° to 158°F)
RH: 5% to 95% RH
Accuracy
Temperature: ± 0.35°C from 0° to 50°C (±
0.63°F from 32° to 122°F), see Plot A
RH: +/- 2.5% from 10% to 90% RH
(typical), to a maximum of +/- 3.5%
including hysteresis. See Plot B.
Resolution Temperature: 0.03°C at 25°C (0.05°F at
77°F), see Plot A
RH: 0.03% RH
Drift Temperature: 0.1°C/year (0.2°F/year)
RH: <1% per year typical
Response
time in airflow
of 1 m/s (2.2
mph)
Temperature: 6 minutes, typical to 90%
RH: 1 minute, typical to 90%
Time accuracy ± 1 minute per month at 25°C (77°F), see
Plot C
Operating
temperature
Logging: -20° to 70°C (-4° to 158°F)
Launch/readout: 0° to 50°C (32° to
122°F), per USB specification
Battery life 1 year typical use
Memory 64K bytes (43,000 12-bit measurements)
Weight 46 g (1.6 oz)
Dimensions 58 x 74 x 22 mm (2.3 x 2.9 x 0.9 inches)
The CE Marking identifies this product as
complying with all relevant directives in
the European Union (EU).
Plot A Plot B
Plot C
Connecting the Logger
The U-Family logger requires an Onset-supplied USB interface
cable to connect to the computer. If possible, avoid connecting at
temperatures below 0°C (32°F) or above 50°C (122°F).
1. Plug the large end of the USB interface cable into a USB port
on the computer.
2. Plug the small end of the USB interface cable into the bottom
of the logger as shown in the following diagram.
If the logger has never been connected to the computer before, it
may take a few seconds for the new hardware to be detected. Use
the logger software to launch and read out the logger.
Important: If you configure the logger to start with a button
start, be sure to press and hold down the button on the front of
the logger for at least three seconds when you want to begin
logging.
You can read out the logger while it continues to log, stop it
manually with the software, or let it record data until the memory
is full. Refer to the software user’s guide for complete details on
launching, reading out, and viewing data from the logger.
Sample and Event Logging
The logger can record two types of data: samples and events.
Samples are the sensor measurements recorded at each logging
interval (for example, the temperature every minute). Events are
independent occurrences triggered by a logger activity. Examples
of events recorded asynchronously during deployment include
when the logger is connected to the host, when the battery is low,
the end of a data file once the logger is stopped, and button pushes.
Press the button on the front of the logger for one second to record
an event. Both a button up and down event will be recorded. This
is useful if you want to mark the datafile at a particular point. For
example, if the logger is located in an incubator, you might press
the button each time the door is opened.
The logger stores 64K of data, and can record up to 43,000
samples and events combined.
Important: Press this
button for 3 seconds
when logger is
launched with Button
Start or press for 1
second to record an
event while logging
USB interface
cable plugged
into logger

HOBO U12 Temp/RH Data Logger
2
Operation
A light (LED) on the side of the logger confirms logger operation.
The following table describes when the logger blinks during logger
operation.
When: The light:
The logger is logging Blinks once every one to four
seconds (the shorter the
logging interval, the faster the
light blinks); blinks when
logging a sample
The logger is awaiting a
start because it was
launched in Start At
Interval, Delayed Start,
or Button Start mode
Blinks once every eight
seconds until launch begins
The button on the
logger is being pushed
for a Button Start
launch
Blinks once every second while
pressing the button and then
flashes rapidly once you
release the button. The light
then reverts to a blinking
pattern based on the logging
interval
Using the RH Sensor
In order to take humidity measurements, the temperature sensor
must be used in conjunction with the RH sensor.
Conditions outside the recommended range may offset the RH
signal. Vapors may also affect the RH sensor. The diffusion of
chemicals into the sensor may cause a shift in both offset and
sensitivity. High levels of pollutants may cause permanent damage
to the sensor.
Upon returning to normal conditions, the RH sensor will slowly
return towards calibration state by itself. However, prolonged
exposure to extreme conditions may accelerate aging and
eventually lead to a permanent shift. To recondition the sensor, do
the following:
1. Remove the battery
2. Warm 24 hours 80–90°C (176–194°F) at < 5% RH
3. Re-hydrate 48 hours 20–30°C (70–90°F) at 75–95% RH
Mounting
There are four ways to mount the logger using the materials in the
mounting kit included with the logger.
Use the hook and loop tape to
affix the logger to a surface.
Attach the magnet and then place
the logger on a magnetic surface.
Use the tie wrap and tie wrap
mount to tie the logger to an
object.
Fasten the logger to a surface
with the two Phillips-head
screws. The back of the logger has two inserts for the screws,
32 mm (1¼ inches) apart.
Protecting the Logger
The logger can be permanently damaged by corrosion if it gets
wet. Protect it from condensation. If it gets wet, remove the battery
immediately and dry the circuit board with a hair dryer before
reinstalling the battery. Do not let the board get too hot. You
should be able to comfortably hold the board in your hand while
drying.
Note! Static electricity may cause the logger to stop logging. To
avoid electrostatic discharge, transport the logger in an anti-static
bag, and ground yourself by touching an unpainted metal surface
before handling the logger. For more information about
electrostatic discharge, visit
http://www.onsetcomp.com/Support/support.html.
Battery
The logger requires one 3-Volt CR-2032 lithium battery. Expected
battery life varies based on the temperature and the frequency at
which the logger is recording data (the logging interval). A new
battery will typically last one year with logging intervals greater
than one minute. Deployments in extremely cold or hot
temperatures or logging intervals faster than one minute may
significantly reduce battery life.
To replace the battery:
1. Disconnect the logger from the computer.
2. Unscrew the logger case.
3. Lift the circuit board and carefully push the battery out with a
small blunt instrument, or pull it out with your fingernail.
4. Insert a new battery, positive side facing up.
5. Carefully realign the logger case and re-fasten the screws.
WARNING: Do not cut open, incinerate, heat above 85°C
(185°F), or recharge the lithium battery. The battery may explode
if the logger is exposed to extreme heat or conditions that could
damage or destroy the battery case. Do not dispose of the logger or
battery in fire. Do not expose the contents of the battery to water.
Dispose of the battery according to local regulations for lithium
batteries.
Onset and HOBO are registered trademarks of Onset Computer
Corporation. Other products and brand names may be trademarks
or registered trademarks of their respective owners.
Light
32 mm
(1¼ inch)