Cleaning solution Thiourea / HCl

Sulfidic buildup (from flue gas desulfurization or wastewater treatment plants): Use a mixture of hydrochloric acid (3 %) and thiocarbamide 5% - 10% (commercially available) and then rinse thoroughly with plenty of clear water.

After cleaning, rinse the sensor thoroughly with water and then recalibrate.
 

Cross-reference of G7CHEM’s Products with other Manufacturers*: 

METTLER TOLEDO:  51350102  1x250ML, 30045062 6x250ML (Exp: 3 years from manufacturer date)