Description

Hanna Instruments' 20-milliliter pH 4.01 standard reference solution packets are specifically formulated for use with electronic pH meters and can be used with most pH, EC, and TDS meters. These ready-to-use, single-dose packets are accurate to 0.01 at 77 degrees Fahrenheit. With Hanna's pH 4.01 Standard Reference Solution you can feel confident your testing meter is reading accurately every time.