Yokogawa SC24V Differential pH ORP Electrode - Manual (Page 16)

IM 12B6J7-02E-E
16
6.3 Maintenance of the SC24V sensor
A pH sensor requires routine maintenance
to keep the measuring elements clean and
functioning. Because the SC24V sensor does
not have an open reference junction and is
hermetically sealed from the process, it does
not suffer from poisoning, diffusion and fouling.
This means the SC24V sensor requires very little
maintenance.
In most cases cleaning with water, iso-propanol
or methanol is sufficient. In other cases the
measuring elements of the sensor have to be
cleaned with specific solutions. Examples:
1. Deposits of limes, hydroxides or carbonates
can be removed by immersing the bottom
part of the sensor in a solution containing
dilute hydrochloric acid (5% is recommended).
Afterwards rinse the sensor with water.
2. Deposits of oil and fat can be removed with
hot water with a detergent. When the results
are unsatisfactory, a mild (carbonate based)
abrasive can be used.
3. Protein deposits should be removed with
a protein enzymatic solution, for instance
a solution containing 8.5 ml concentrated
hydrochloric acid and 10 grams of pepsin in
1 liter of water.
A soft toothbrush may be used to accelerate the
cleaning process.
Note: Avoid cleaning with non-polar solvent like
tri-chloro ethylene, toluene or hexane.
The non-polar solvents will break up the
gel-layer on the measuring glass elements
and requires that the sensor has to be
soaked in water for at least
12 hours before it will function again.
7 MODEL CODE
Model Code Suffix Code Option Code Description
SC24V
Combined 12mm 4 in 1 differential pH sensor
with Variopin connector
Type - ALN26 Ag/AgCl reference system, pH half cell L-glass,
reference cell salt sensitive glass, non-flow, heavy duty
Sensor length - 120 120 mm
- 225 225 mm
Sensor is standard equipped with a slide ring (Ryton) and an O-ring (Silicon) for mounting in adapters
(see Section 3.3). These parts and other O-ring materials are available as a spare part.