When using the precision test strip 5.5-9 for the first time, open the plastic box and pull the length of the built-in wrapping paper to a certain length so that it protrudes through the notch on the side of the plastic box and close the plastic box.

According to the situation, pull out any length of test paper and tear it off (note that a certain length of test paper should be left outside the plastic box so that it can be pulled out for the next time).

The test strip is immersed in the solution to be tested, and after half a second, it is compared with the standard color plate to obtain the pH value. When measuring suspensions, colored liquids, and viscous liquids, it is advisable to apply an appropriate amount of drops on one side of the test strip and compare the color on the other side with the standard color version to obtain the pH value.