This prevents reference cell contamination that can cause drift

Built-in bypass valve for easy

Grip: Silicone band

ready to dispense through the convenient stainless steel spigot

TDS and Temp

Hanna Instruments HI7004L 4.01 pH Calibration Buffer Solution, 500mL Bottle whole house filter with cartridge This prevents reference cell contaminationThis buffer value is widely used in water purification plants, in the food industry, and wherever the pH is expected to be slightly acidic. Traceable to NIST standards Available in bottles or sealed sachets, complete with or without a certificate of analysis. Multiple resolutions for better accuracy. NIST Traceability Standardized using a pH meter calibrated by means of two standard solutions prepared from NIST standard reference materials. Color