Confidence in your turbidity results Hach was the first to apply formazine as a turbidity standard in the drinking water industry, more than 40 years ago. Hach's Stablcal stabilized formazine turbidity standards are true formazine dilutions developed for use in any turbidimeter. Stablcal turbidity standards are USEPA accepted for calibration purposes.

• Precise, pre-mixed formazine solutions for highly accurate results
• Based on formazine primary standards to ensure high purity
• Enhanced stability saves time and labor