HOBO MX pH and Temperature Logger (MX2501) Manual
U.S. and International Sales: 1-508-759-9500 10
www.onsetcomp.com
3.
Use a foam swab dipped in water to clean the internal O-
rings. Use the foam swab to spread a small dot of silicone-
based grease along both the O-rings inside the sensor end
cap. Do not use a cotton swab as the fibers on the swab can
interfere with the operation of the electrode.
4.
Remove the replacement pH electrode from the shipping
bottle and wipe the outer plastic body dry with a soft paper
or cloth towel.
Never touch the glass bulb inside the clear
plastic end of the probe.
5.
Remembering not to touch the glass bulb, push the pH
electrode
gently and slowly
into the sensor end cap. You
will feel the pH electrode pause as it passes through two
internal O-rings inside the sensor end cap (shown with step
3). Make sure the internal O-rings are still in place as the
probe is pushed into the sensor end cap.
Note:
If done too
quickly, this process can unseat the internal O-rings.
Gently twist the electrode so that the holes in the clear
electrode body line up with the holes in the end cap.
6.
Continue to gently push the electrode into place until the
clear plastic is fully seated in the end cap as shown.
7.
Push the sensor end cap back into the logger, making sure
the small tab in the end cap fits in the small groove in the
logger housing. Use the large tab on the end cap and the
arrow on the logger housing to help with proper alignment.
Do not twist or turn the end cap as you push it straight into
position.
8.
If you will be calibrating the logger immediately:
screw the
closure cap back on the logger and follow the instructions in
Calibrating the Logger
.
If you will not be calibrating or deploying the logger
immediately:
a.
Pour storage solution into the clear storage cap to the
marked fill line.
b.
Carefully screw the cap with storage solution onto the
logger.
Important:
Keep the sensor in storage solution unless you are
calibrating the logger or deploying it in water. Only use storage
solution in the cap; do not use water. Do not use the copper
guard while the sensor is in the cap.
Battery Information
The logger requires one user-replaceable AA 1.5 V alkaline or
lithium battery. With a logging interval of 1 minute and at 25°C
(77°F)
,
battery life is 1 year with Bluetooth Always On selected
and 3 years with Bluetooth Always Off selected. Expected battery
life varies based on the ambient temperature where the logger is
deployed, the logging interval, the frequency of connections,
downloads, and paging, and the use of burst mode or statistics
logging. Deployments in extremely cold or hot temperatures or a
logging interval faster than 1 minute can impact battery life.
Estimates are not guaranteed due to uncertainties in initial
battery conditions and operating environment.
pH electrode installed
Use a foam swab dipped in
water to clean the internal
O-rings; use a foam swab
to spread a dot of silicone-
based grease on the
internal O-rings
Push the end cap
back into logger,
aligning tabs with
arrow
Sensor end cap
installed with
correct alignment
Large tab
Small tab
Small groove
Gently and slowly
push pH
electrode into end cap and
twist the electrode so the
holes in the electrode align
with the holes in the end cap
Pour storage
solution into the
cap to the fill line
Screw on the
filled cap
