Thermo Scientific AquaSensors™ DataStick™ Measurement System User Guide
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4 . 1 . 5 . 1
P H 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
®
material. Custom salt bridge chemistry can be provided on request. The salt bridge
options can also be used on ORP sensor heads.
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)
