Procedure for Cleaning and Maintenance




Conditions to avoid (Back to top)

  • When the bottle with the storage solution is removed of your sensor, completely unscrew the cap;

  • Be very careful when handling the analytical sensor, it is constructed of glass and has parts, like the bulb, which are very sensitive to mechanical action. A hit in the bottom of a Becker glass, for example, is enough to damage the workpiece;

  • Never scrape or sand the glass surface (bulb) of the electrode;

  • Do not leave your sensor (pH, ORP or conductivity) out of the storage solution for more than six hours. This may compromise the response speed of play or disables it;

  • Never store your pH or ORP sensor in deionized water. Observe the recommended storage solution for sensor type of pH, ORP and reference; just conductivity cells should be placed in deionized water;

  • Buildup on the glass surface (bulb) or on reference system (ceramic joints), will impede a correct reading;

  • Avoid extreme conditions, whenever possible, and be aware of the limitations of use of each specific model of sensor you are using. Elevated temperatures, as well as measurements in strong acids or caustic solutions reduce the lifetime of the sensor;

  • Never expose the electrode to temperatures below -12 º C.




Care and Maintenance of pH electrodes\Reference\ORP\Conductivity (Back to top)

  • The analytical sensors generally require periodic maintenance to ensure the quality of their readings and extend their lifespan.

  • Maintain the electrode, when not in use, immersed in the solution packaging. Following indications:
    • •   pH sensors, ORP or reference with internal electrolyte KCl 3 mol/AgCl - packaging solution KCl 3 mol (SSE02).

    • •   pH sensors or reference to internal electrolyte KNO ³ - solution packing KNO3 (SSE05).

    • •   pH sensors for alcohol with internal electrolyte LiCl 2mol. - Packaging solution 2 mol LiCl in ethanol (SSE01).

    • •   Conductivity Cells for all constants - using deionized water.

  • Maintain the level of the internal electrolyte always near the hole filling.

  • Shielded Sensors do not require completion of the internal electrolyte.

  • Always use the inner electrolyte recommended by the manufacturer.

  • After use, wash the sensor with deionized water to remove any deposits that may be deposited therein.

  • Remove the inner electrolyte whenever the sensor presents slope less than 95%, or even when used in very aggressive or contaminated systems.



Cleaning pH electrode/reference (Back to top)

  • Deposit salts: dissolve the deposits by immersing the electrode in clean water for 10-15 minutes.

  • Oils and greases: Carefully wash the bulb of electrode with biodegradable neutral ph detergent and water until all the fat is removed.

  • Reference junction clogged by dry salt: heat a solution of KCl 3 mol (SSE02) up to a maximum of 50 ºC and keep the sensor immersed for up to 10 minutes. Allow the electrode to cool naturally.

  • Contaminated reference junction: use the Thioureia (SSL02)solution. Leave the electrode immersed in the solution for 30 minutes.

  • Protein Deposits: use Pepsin solution (SSL01). Leave the electrode in the solution at most between 5 and 10 minutes.

  • Slope less than 95% for the electrodes "refillable" - Remove internal electrolyte through the hole filling, with a syringe. Rinse the piece internally with deionized water 3 times. With internal reference system cleaned, fill the sensor with a new internal electrolyte (SSE01, SSE02 or SSE05). This procedure also should be repeated for 3 times before use.

  • After each of the procedures listed above, rinse the piece with deionized water in abundance, dry it carefully with absorbent paper towel and let the electrode resting on its packaging solution for 24 hours.

  • The above procedures may not be sufficient for restoring the quality of a measuring sensor and such inefficiency is not regarded as a defect likely to be guaranteed.




Cleaning ORP Electrode (Back to top)

  • Bulb ORP electrode (metal rod): can be gently cleaned with damp paper, dry silicon or carbide, iron oxide, emery cloth, iron oxide or fine metal wool fibers.

  • Deposit salts: dissolve deposits by immersing the electrode in clean water for 10-15 minutes.

  • Oils and greases: Carefully wash the bulb of electrode with biodegradable neutral ph detergent and water until all the fat is removed.

  • Reference junction clogged by dry salt: heat a solution of KCL 3 mol (SSE02) at maximum of 50 º C and keep the sensor immersed for up to 10 minutes. Allow the electrode to cool naturally.

  • Reference junction contaminated: use the Thioureia (SSL02)solution. Leave the electrode immersed in the solution for 30 minutes.

  • Deviation above +15 mV: for "refillable" electrodes - Remove internal electrolyte through the filling hole, with a syringe. Rinse the piece internally with deionized water 3 times. With reference system internal cleaned, fill the sensor with a new internal electrolyte (SSE01). This procedure also should be repeated for 3 times before use.

  • After each of the procedures listed above, rinse the piece with deionized water in abundance, dry it carefully with absorbent paper towel and let the electrode resting on its packaging solution for 24 hours.

  • The above procedures may not be sufficient for restoring the quality of a measuring sensor and such inefficiency is not regarded as a defect likely to be guaranteed.




Cleaning Conductivity Cell (Back to top)

  • You can use deionized water or biodegradable neutral detergent.

  • For more specific cleaning, you can use a mixture of one part by volume of isopropyl alcohol, a portion of ethyl ether and one part of HCL 0.1 mol. After cleaning, thoroughly rinse the cell with deionized water.

  • More severe procedures predict the remove of platinum black film, with application of aqua regia electrode or electrolysis in HCl.

  • For cells without platinum black or removed, it is necessary a new platinization.

  • Platinization Procedure:
    • •   Platinization solution: Dissolve 1.0g of chloroplatinic acid PA ( H2PtCl6*6H2O) and 0.012g of lead acetate P.A (CH³COO2) in 100 ml of deionized water. This solution can be reused multiple times.

    • •   Immerse the conductivity cell in this solution and connect one wire to the negative pole and the other to the positive pole of a dry cell of 1.5 V. Maintaining immersed until one of the platinum plates is completely platinizaded. Invert the poles and perform the procedure again. Rinse the electrode with deionized water.

  • After each of the procedures listed above, rinse the piece with deionized water in abundance, dry it carefully with absorbent paper towel.

  • The above procedures may not be sufficient for restoring the quality of a measuring sensor and such inefficiency is not regarded as a defect likely to be guaranteed.