Trademark Class 01. Chemical test paper belongs to trademark class 01. Class 01 trademark transfer mainly includes: industrial gases, simple substances, industrial chemical raw materials used in industry, science, agriculture, horticulture, and forestry, radioactive elements and their chemicals, used in industry, science Chemicals, chemical preparations, chemicals for products not belonging to other categories, chemicals used in agriculture, horticulture, and forestry, chemical preparations, chemical reagents, chemicals and materials for photography, unprocessed artificial synthetic resins, unprocessed artificial synthetic resins, Processed plastic substances (excluding unprocessed natural resins), fertilizers, fire-extinguishing and fire-proofing compounds, quenching chemical preparations, welding chemical preparations, food and pharmaceutical chemicals (excluding food preservative salts), tanning materials and leather Chemicals, industrial adhesives and glues (excluding paper adhesives), pulp, energy. Therefore, pH test paper invoicing belongs to trademark class 01. pH test paper is a product for testing the pH of a solution. It is a kind of ready-made test paper. When using it, tear off a strip and put it in a watch glass. Use a dry glass rod to dip a drop of the solution to be tested. Use a rubber dropper to draw the solution and drop it on the middle of the test paper. Then according to the test paper By comparing the color change with the standard color card, you can know the pH of the solution, which is very convenient.