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HANNA Marine pH Handheld Colorimeter


pH of ocean surface water is normally 8.5 pH.

Over the years however, acidification tendency is to decrease 0.1 to 0.2 pH units/century. Acidification is a consequence of carbon dioxide (CO) absorption in seawaters and oceans. Carbon dioxide reacts with seawater to produce carbonic acid (HCO).

pH modifications affect marine life growth, reproduction, and communication. Hydrogen ions have a tendency to bond with carbonate to form bicarbonate. The greater attraction to carbonate over calcium can adversely affect skeleton building and can limit coral growth.


Specifications list


Range 6.3 to 8.6 pH
Resolution 0.1 pH
Accuracy @ 25°C/77°F ±0.2 pH
Light Source LED @ 525 nm
Light Detector silicon photocell
Method colorimetric adaptation of phenol red method
Auto-off after ten minutes of non-use
Environment 0 to 50°C (32 to 122°F); RH max 95% non-condensing
Battery Type (1) 1.5V AAA
Ordering Information HI-780 Checker HC is supplied with sample cuvettes with caps (2), pH reagent starter set, battery, and instructions
Accessories purchased separately HI-780-25 Reagent set for approx. - 100 tests. HI-780-11 Calibration set