free chlorine test kit for water analysis

In the water and by the pool free (active) chlorine ppm (mg/l)
- denominated measures.

the test for free chlorine (o-tolid for):

1 - a petri dish with 10 ml. fill in sample .

2 - 2 drops On the O-tolid the shake and damlatip

wait for 5 minutes .

3 - yellow compare with color scale.

in December, normal 0.5 - 1.0 ppm