Scope of Application Suitable for urine, saliva, and water quality testing. Characteristic Resists VC interference. How to Compare Acidity & Alkalinity 1. Check the closest colors of the top and bottom squares. 2. Find the midpoint number between the two corresponding values on the color chart—this is the final pH. 3. Often, average the two colors by taking the midpoint to get the result. 4. If the color doesn’t match the chart, observe undertones (e.g., orange in yellow, blue in green) to judge. Storage & Expiration 1. Unopened: Store in a dry, dark place at 2–30? (2–8? preferred); shelf life 24 months. 2. After Opening: Seal tightly, store in dry, dark place at 2–30?; valid for 6 months. Notes 1. Optimal colorimetric time: 15s (too long/short affects reading). 2. Avoid touching the test strip’s reaction end to prevent contamination. 3. Seal remaining strips in dark after taking the needed amount. 4. For testing: Use colorless/light-colored liquids. Dark liquids: Adsorb with activated carbon and dehydrate. Turbid liquids: Let settle, use the clear part.