Hanna Checker®HC Alkalinity colorimeter (ppm)
Standard test kits are limited with accuracy since they depend upon the human eye to discern colors. The Hanna HI755 handheld colorimeter eliminates the struggle of matching to a color chart by providing a direct saltwater alkalinity result in ppm CaCO3 (alkalinity).
Crucial in marine environments, alkalinity provides both the carbonate ion required for calcium carbonate skeletal regeneration of coral reefs, as well as a pH buffer against large changes in acidity. 
Designed as a more accurate alternative to chemical test kits, the HI755 provides quick, accurate results in a few easy steps.
Sepcifications:
Range : 0 to 300 ppm CaCO₃
Resolution : 1 ppm
Accuracy @ 25°C : ± 0.3 dKH ±5/ of reading
Light Source : LED @ 610nm
Light Detector : silicon photocell
Battery Type : (1) 1.5V AAA
Auto-off : after 10 minutes of non-use
Environment : 0 to 50°C ; RH max 95% non-condensing
Dimensions : 86.0 x 61.0 x 37.5 mm
Weight : 64 g
Calibration Set : HI755-11 Not included
Warranty : 1 year
What's inculded
1x HI772 Checker®HC 
2x sample cuvettes with caps
1x HI-755-26 reagent (25 tests)
1x syringe with tip
1x batteries
1x instructions, and quick start guide.