pH4 pH 7 calibration solution 50 ml each for pH measuring devices pH 4 pH 7 50 ml each calibration liquid buffer solution calibration solution for pH measuring device Can be used immediately, no stirring/mixing necessary Ideal for the aquarist Long shelf life, batch certificate available upon request Suitable for devices from all manufacturers very precise - at the specified temperature the pH value deviates from the specified value by a maximum of ± 0.015 pH.
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