The HI-3812 test kit tests the hardness level as mg/L (ppm) calcium carbonate, via an EDTA (ethylene-diamine-tetraacetic acid) titration.During testing, when colour change is achieved, under careful conditions - usually using a burette - the reagent is added, drop by drop, until the solution turns to the colour required. The user will then count how many drops of reagent were used to achieve complete colour change. The number of drops used will determine the chemical concentration and results can be found in the manual included.

• Supplied with 30mL hardness buffer, 10mL calmagite indicator, 120mL EDTA solution, 20mL plastic beaker with cap and 50mL plastic beaker with cap, 1mL syringe with tip
• Method: titration
• Range 0.0 - 30.0mg/L, 0 - 300 mg/L
• Smallest increment: 0.3mg/L, 3 mg/L
• Chemical method: EDTA
• Weight: 460g