Thermo Scientific Scientific AquaSensors DataStick User Manual page 50

Caution: When using dangerous chemicals such as hydrochloric acid or chlorine bleach,
use all appropriate safety precautions, especially eye protection.
Before returning the sensor to service, allow it to soak in water or buffer at ambient temperature for about an hour to stabilize.
After cleaning the sensor, always calibrate the sensor head before installing in the process.
4 . 2 . 4 . 1 O R P S E N S O R R E F U R B I S H M E N T –
R E P L A C I N G T H E S A L T B R I D G E A N D R E F E R E N C E S O L U T I O N .
If the sensor head has been cleaned and calibration cannot be achieved, replace the salt bridge and
reference solution.
Hold the sensor firmly with the electrode tip facing upwards. Remove the existing salt bridge by using
a 15/16 wrench (24mm) and turning it counterclockwise. Dispose of the salt bridge using an approved method.
Pour out the old reference filling solution. Rinse the reservoir with distilled or de-ionized water.
Slowly fill the reservoir with Thermo Scientific AquaSensors Reference Filling Solution (P/N RCS02) so the solution
just covers the reference O-ring.
Slowly screw the new salt bridge clockwise onto the sensor head until secure. Tighten the salt bridge with
a 15/16 wrench (24mm) until snug.
After replacing the salt bridge and reference solution, calibrate the sensor.
If after cleaning and refurbishment sensors still have slow responses, low measurement slopes or are
seriously abraded or scratched, they must be replaced. Contact your local distributor or call Thermo Fisher
Scientific Customer Service.
There are several salt bridge replacement options. Protected and unprotected electrodes (with face seals for sanitary
applications). CPVC and PEEK
options can also be used with pH sensor heads.
Thermo Scientific AquaSensors™ DataStick™ Measurement System User Guide
Do not overfill. Overfilling will lead to
excessive pressures that will affect the
junction potentials of the reference.
Do not over tighten.
Maximum torque: 10 lbs⋅in (1.1 N⋅m)
material. Custom salt bridge chemistry can be provided on request. The salt bridge
®
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