In-Situ TROLL 9500 Operators Manual - Manual (Page 108)

101
TROLL 9500 Operator’s Manual 0095110 rev. 007 01/09
sensor
removal
tool
USAGE RECOMMENDATIONS AND CAUTIONS
s
rected because, unlike pH, the ORP value depends on the activity
of many ions in solution. pH values are more easily corrected
because they are due to the activity of one ion, H
+ .
SENSOR CARE AND HANDLING
SENSOR REMOVAL
Use the sensor removal tool to pop the sensor out.
MAINTENANCE/INSPECTION/CLEANING
If the platinum ORP sensor appears dull or fouled, it may be cleaned
with a swab dipped in alcohol. Rub gently until the platinum appears
shiny. Rinse in clean water.
If a film develops on the glass electrode, or if the sensing glass or
junction become dehydrated, the response may be sluggish or erratic,
or the sensor may fail to calibrate. In these cases, rinse the sensor
in 90% isopropyl alcohol, then soak in storage solution (Catalog No.
0065370) for at least an hour, overnight if needed. If this does not re-
store the response, try soaking in 0.1 M HCl solution for 5-10 minutes,
followed by a thorough rinse in clean water. If the response has still
not improved, replace the filling solution, or the junction.
Note: The following maintenance instructions apply to In-Situ’s newest
pH/ORP sensor (cat. no. 0059520). Older sensors (cat. no. 0032010
& 0032020, now discontinued) are not user-serviceable.
REPLACING THE FILLING SOLUTION
Replace the filling solution every 5-6 months, or when:
s
1. Unscrew the reference junction as shown.
2. Holding the sensor at an angle, shake out the old filling solution.
3. Protect the connector end of the sensor with the soft cap it shipped
with, or wrap the sensor in a paper towel to
prevent solution from entering the connector.
4. Using the dispenser cap on the filling solution bottle,
insert the tube into the bottom of the empty reservoir.
Squeeze a steady stream of solution into the reservoir until
IT
Continue to add solution while withdrawing the tube.
5. Screw in the reference junction, and hand-tighten until snug. Some
lLLING
6. Soak the sensor in tap water for at least 15 minutes.
7. Recalibrate the sensor.
If necessary, thoroughly clean the electrical connector to
remove filling solution: Using a disposable pipette, fill the
connector with isopropyl alcohol (70% to 100%). Shake to
dry. Repeat 3 times. Dry overnight. When thoroughly dry, recalibrate.
REPLACING THE JUNCTION
Replace the junction when the sensor fails to calibrate, even after
replacing the filling solution.
1. Unscrew the reference junction and discard.
2. Replace the filling solution and screw in a new reference junction
as described above.
3. Soak for 15 minutes in tap water, then recalibrate the sensor.
TIP: Keep the junction damp at all times to avoid a lengthy
rewetting process.
STORAGE
Short-Term Storage (several days)
Store in the Cal Cup in tap water.
Long-Term Storage (up to several weeks)
Remove the sensor and store in the electrode storage bottle with
10-20 mL of storage solution (Catalog No. 0065370). Tighten the cap
to prevent drying. Prior to use, condition the sensor by rinsing with
deionized or tap water and soaking for 15 minutes.
REFERENCES
Eaton, A.D., L.S. Clesceri, E.W. Rice, and A.E. Greenberg, eds.,
Standard Methods for the Examination of Water and Wastewater,
21st edition, Washington, D.C.: American Public Health Associa-
tion, American Water Works Association, and Water Environment
Federation, 2005. Section 2580, Oxidation-Reduction Potential.
SECTION 14: ORP