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1 M HCl
Chlorine
bleach
Advanced Cleaning
For moderate contamination or slow response after advanced rinsing, remove the
sensor from the bulkhead and perform the following steps:
1.
Remove any foreign matter from the sensor tip. If necessary, use a
moistened cotton swab to carefully remove foreign material from the glass
bulb and junction. Be careful to avoid direct contact with the glass bulb.
The bulbs are fragile and will break if pressed with sufficient force.
2.
Soak for 10 minutes in a mild solution of clean water and dish soap. Rinse
the sensor with tap water and inspect.
If contaminants are removed, attach the sensor to the bulkhead and test the
response time.
If contaminants remain or response time does not improve, continue to the
hydrochloric acid (HCl) soak.
1 M HCl
Chlorine
bleach
Acid Soak
For heavy contamination or slow response after advanced cleaning, remove the
sensor from the bulkhead and perform the following steps:
1.
Soak the sensor for 30 to 60 minutes in one molar (1 M) HCl. HCl reagent
can be purchased from most chemical or laboratory distributors. To
prevent injury, carefully follow the HCl manufacturer’s instructions. If HCl is
not available, soak in white vinegar.
2.
After soaking, thoroughly rinse the sensor with tap water. Then soak the
sensor in clean tap water for 60 minutes, stirring occasionally. Finally, rinse
the sensor once again with tap water.
Attach the sensor to the bulkhead and test the response time. If response
time does not improve or biological contamination of the reference junction is
suspected, continue to the chlorine bleach soak.
1 M HCl
Chlorine
bleach
Bleach Cleanse
If biological contamination of the reference junction is suspected or if good
response is not restored by the previous methods, remove the sensor from the
bulkhead and perform the following steps:
1.
Soak the sensor for 60 minutes in a 1:1 dilution of chlorine bleach and tap
water.
2.
After soaking, thoroughly rinse the sensor with tap water. Then soak the
sensor in clean tap water for 60 minutes. Finally, rinse the sensor once
again with tap water.
Attach the sensor to the bulkhead and test the response time. If response time
does not improve the sensor may be nearing the end of its useful life.
Sensors, Calibration, and Maintenance