7$
Testing method:
1. Immerse the reaction area of the test strip in the solution to be tested for 1-2 seconds, take out the test strip, draw the edge of the test strip along the wall of the solution container, and remove the excess water on it.
2. After 1 minute, compare the color of the reaction zone of the test strip with the color of the color chart to determine the test value of the solution to be tested.
3. The color comparison time is best controlled at 60s, too long or too short will affect the reading.
Product :
the product comes in a black container with 50 strips
