CI Sulfite Titrant High is a standardized analytical titrant for measuring high-range sulfite residuals in boiler and feedwater systems where sodium sulfite is used as an oxygen scavenger. In a 25 mL sample, each drop equals 10 ppm as Na₂SO₃, giving operators a fast, repeatable way to verify whether sulfite residual is actually sitting inside the intended control range. That matters because sulfite only protects the system when enough excess residual is being maintained to keep dissolved oxygen under control; if the residual falls too low, corrosion risk rises, and if it runs too high, the plant is simply overfeeding chemistry without added benefit. Formulated for dependable field and plant use, mercury-free, and supplied in a practical 1-litre format, CI Sulfite Titrant High fits directly into routine boiler monitoring and dissolved-oxygen control programs where accurate residual management drives corrosion protection, system stability, and operating discipline.