User Manual

HOBO
®
U12 Temp/RH/Light/
External Data Logger
(Part # U12-012)
© 2009–2010 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.
Inside this package:
• HOBO U12 Temp/RH/
Light/External Data Logger
• Mounting kit with magnet, hook
and loop tape, tie-wrap mount,
tie wrap, and two screws.
Doc # 13128-B,
MAN-U12012-web
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/Light/
External Data Logger is a four-channel logger with 12-
bit resolution and can record up to 43,000
measurements or events. The external channel accepts a
wide range of Onset and third-party sensors/transducers
with a 0-2.5 VDC output, including external
temperature, AC current, pressure, air velocity, and kW
sensors. Specifications for Onset sensors can be found
at www.onsetcomp.com or by contacting your Onset
Authorized Dealer. For 0-5 VDC, 0-10 VDC, or 4-
20mA output, use optional Onset Part No. CABLE-
ADAP5, CABLE-ADAP10, or CABLE-4-20mA
respectively.
The logger uses a direct USB interface for launching
and data readout by a computer. Onset software 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
Light intensity: 1 to 3000 footcandles (lumens/ft
2
)
typical; maximum value varies from 1500 to 4500
footcandles (lumens/ft
2
)
External input channel (see sensor manual): 0 to
2.5 VDC; 0 to 5 VDC (with CABLE-ADAP5) and 0
to 10 VDC (with CABLE-ADAP10)
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%.
See Plot B.
Light intensity: Designed for indoor measurement
of relative light levels, see Plot D for light
wavelength response
External input channel (see sensor manual): ± 2
mV ± 2.5% of absolute reading
Resolution Temperature: 0.03°C at 25°C (0.05°F at 77°F),
see Plot A.
RH: 0.03% RH
External Input Channels: 0.6 mV
Drift Temperature: 0.1°C/year (0.2°F/year)
RH: <1% per year typical; RH hysteresis 1%
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 Plot D
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.