Starting at $63.75
As of April 1, 2022, HF Scientific has added a 8% surcharge for all of their products. The surcharge will appear as a separate line item on each sales order.
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  • Biodegradable
  • No formazin formula
  • Factory certified by HF scientific for use in the Hach® 1720 c/d/e Series Online Turbidimeters
  • Custom NTU values and quantities available


ProCal turbidity standards are pre-diluted, factory certified, and ready for use with not only the HF scientific turbidimeter product line but with other manufacturer's instrumentation. The ProCal standard formulation utilizes a preservative that enhances stability, yet is safe and biodegrades rapidly in aquatic environments.