HOBO U12 Deep Ocean Temperature Logger Manual
1-800-LOGGERS (564-4377) • 508-759-9500
www.onsetcomp.com • loggerhelp@onsetcomp.com
© 2011 Onset Computer Corporation. All rights reserved. Onset,
HOBO, and HOBOware are trademarks or registered trademarks of
Onset Computer Corporation. All other trademarks are the property
of their respective companies.
14767-A MAN-U12-015-03
for protection. Because pressure, temperature, and duration of deployment can affect O-rings and backup rings over time, it is important
to inspect the rings before a new deployment. Replace the rings if they are beginning to deform in shape or if you have any doubt about
the integrity of the seal. To replace the rings:
1.
Unscrew the end-cap and remove the orange and blue rings. You may need to use a plastic O-ring tool or similar plastic tool to
remove the blue O-rings. Do not use a screwdriver or sharp metal tool as this could damage the O-ring grooves.
2.
Clean the two grooves on the end-cap with isopropyl alcohol.
3.
Lightly lubricate the blue O-rings with the silicone-based O-ring lube (included).
4.
Work one blue O-ring with your fingers or a plastic O-ring tool over the thread into the first O-ring groove and up into the second
O-ring groove (flush with the end-cap flange). Do not use a screwdriver or sharp metal tool as this could damage the O-ring groove or
the O-ring itself.
5.
Install the next blue O-ring over the thread and up to the flange that separates the two grooves.
6.
Next, install the orange backup rings below each O-ring. The backup rings are “scarf” cut to make them easier to install.
7.
Screw the end-cap back onto the logger. Make sure the backup rings are seated properly when the end-cap is screwed into the logger
housing. The end-cap must be securely in place with no visible gap between the housing and the end-cap.
Note:
Static electricity may cause the logger to stop logging.
To avoid electrostatic discharge, always transport the logger 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 “static discharge” in the FAQ section on onsetcomp.com.
End-cap with the correct order of O-rings and backup rings
Assembled end-cap
End-cap flange
Backup ring: install in first O-ring groove against O-ring
O-ring: install in first O-ring groove against flange separating two grooves
Backup ring: install in second O-ring groove against O-ring
O-ring: install in second O-ring groove against end-cap flange
First O-ring groove
Second O-ring groove
Thread
Flange separating two grooves
