Hobo U12 User manual

HOBO®U12 Stainless Temp Data Logger
(Part # U12-015, U12-015-02)
© 2003–2011 Onset Computer Corporation. 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.
7938-G MAN-U12-015
Inside this package:
•HOBO U12 Stainless Temp
Data Logger (U12-015)
or
HOBO U12 Stainless Temp
Data Logger with 5" Probe
(U12-015-02)
•O-Ring Replacement Kit
(U12-015-ORING-E
[EPDM] and U12-015-
ORING-V [Viton])
Thank you for purchasing a HOBO data logger. With proper care, it will give you
years of accurate and reliable measurements.
The HOBO U12 Stainless Temp Data Logger is a single-channel temperature
logger with 12-bit resolution that can record up to 43,000 measurements. 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 -40° to 125°C (-40° to 257°F)
Accuracy ± 0.22°C at 25°C (± 0.4°F at 77°F), see Plot
A
Resolution 0.025°C at 25°C (0.045°F at 77°F), see Plot
A
Drift 0.05°C/year + 0.1°C/1000 hrs above 100°C
(0.09°F/year + 0.2°F/1000 hrs above 212°F)
Response time in 1
m/s (2.2 mph) airflow
U12-015: < 10 minutes, typical to 90%
U12-015-02: 2.25 minutes, typical to 90%
Response time in
water
U12-015: < 3.5 minutes, typical to 90%
U12-015-02: 20 seconds, typical to 90%
Time accuracy ± 2 minute per month at 25°C (77°F), see
Plot B
Operating
environment Air, water, steam, 0 to 100% RH
Operating
temperature
Logging: -40° to 125°C (-40° to 257°F)
Launch/readout: 0° to 50°C (32° to 122°F),
per USB specification
Battery life 3 year typical use, factory replaceable
Memory 64K bytes (43,000 12-bit measurements)
Construction Food-grade 316L stainless steel
Weight U12-015: 72 g (2.5 oz)
U12-015-02: 82 g (2.9 oz)
Logger dimensions 17.5 x 101.6 mm (0.69 x 4.00 inches)
Probe dimensions
(U12-015-02 only) 4 x 124 mm (0.16 x 4.90 inches)
Pressure/depth rating 2200 psi (1500 m/4900 ft) maximum
Vibration rating Navy spec: NAVMAT P-9492
(non-probe model only)
NIST certificate Available for additional charge; temperature
range -30° to 120°C (-22° to 248°F)
The CE Marking identifies this product as
complying with all relevant directives in the
European Union (EU).
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
-40-200 20406080100120
Tem perature (°C)
Accuracy/Resolution(°C)
Accuracy
Resolution
Plot A
-400
-300
-200
-100
0
100
200
-40-20 0 20406080100120
Temperature (°C)
Time Base Error (PPM)
-17.3
-13.0
-8.6
-4.3
0.0
4.3
8.6
Time Base Error (Min/Month)
Plot B
Connecting the logger
The U-Family logger requires a 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. Remove the stainless steel end-cap from the logger by
turning it counter-clockwise. If the cap is difficult to turn,
place the stem of a small screwdriver through the hole in
the end-cap for better leverage.
2. Plug the large end of the USB interface cable into a USB
port on the computer.
3. Plug the small end of the USB interface cable into the
logger as shown in the following diagram.

HOBO U12 Stainless Temp Data Logger
2
4. If the logger has never been connected to the computer
before, it may take a few seconds for the new hardware to
be detected.
5. Use the logger software to launch the logger. (The first
time you launch the logger, the deployment number will be
greater than zero. Onset launches the loggers to test them
prior to shipping.)
6. 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.
Important: USB communications may not function properly
at temperatures below 0°C (32°F) or above 50°C (122°F).
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, and the end of a data file once the
logger is stopped.
The logger stores 64K of data, and can record up to 43,000
samples.
Mounting
A 4.8 mm (3/16") diameter hole is provided in the end-cap to
secure the logger to an object.
Care and maintenance of the logger
The logger can be permanently damaged by internal corrosion
from condensation or foreign matter entering the case. The
logger is shipped with an installed EPDM O-ring. (Refer to the
chart in the included O-ring Replacement Kit for information
about specific O-ring applications.) The logger electronics
depend upon the integrity of the O-ring seal for protection.
Prior to every deployment, the O-ring should be inspected for
cracks or tears, and for proper lubrication. The O-ring’s
surface should be smooth and lightly lubricated. If needed, the
O-ring should be re-lubricated or replaced. In addition, the
end-cap must be securely in place with no visible gap between
the housing and the end-cap. Before opening the end-cap for
read out, make sure that the logger is clean and dry. The
logger should always be capped when it is not connected to
the computer.
316L stainless steel has good corrosion resistance, but it can
be damaged by contact with dissimilar metals or through
crevice corrosion. The logger should not be deployed in salt or
brackish water, or the housing will eventually fail and water
will destroy the electronics. If long-term deployment in salt
water is required, place the logger in a sealed bladder
containing a non-corrosive liquid. Always rinse the logger
with fresh water after deployment in salt or brackish water.
On the U12-015-02, the 5" piercing probe can be bent and/or
broken with excessive force. Damage to the 5" probe is
expressly not covered by the product warranty, and cannot be
repaired.
Note! Static electricity may cause the logger to stop
logging. To avoid electrical static discharge (ESD), transport
the logger only with its end-cap on, or in an anti-static bag.
Ground yourself by touching an unpainted metal surface
before handling the logger. For more information, search for
“electrical discharge” in the FAQ section on onsetcomp.com.
Battery
Expected battery life varies based on the temperature and the
frequency at which the logger is recording data (the logging
interval). With 60 minutes of operation at 125°C (257°F) per
day, a new battery will typically last approximately three years
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.
The logger has the ability to report and log its own battery
voltage. If the battery falls below 3.1 V, the logger will record
a “bad battery” event in the datafile. If the datafile contains
“bad battery” events, or if logged battery voltage repeatedly
falls below 3.3 V, the battery is failing and the logger should
be returned to Onset for battery replacement.
Do not attempt to replace the battery. If the battery needs to be
replaced, contact Onset or an Onset Authorized Dealer for
factory replacement battery service.
WARNING: Do not cut open, incinerate, heat above
150°C (302°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.