Acid discharge meter (pH meter) and sand scraper are two commonly used instruments in laboratory or scientific research. Their main difference lies in their applications and functions:

1. Acidimeter (acidity meter):

Acid discharge meter, also known as acidity meter, is used to measure the pH of substances. The pH meter determines the pH value of the solution by measuring the concentration of hydrogen ions (H+) in the solution. Acidimeter usually consists of electrode and instrument body. The electrode can be a glass electrode or a combined electrode, which is responsible for measuring the concentration of hydrogen ions in the solution and transmitting the data to the instrument body for display and recording. Acidimeter is widely used in chemistry, biochemistry, environmental science and other fields.

2. Sand scraper:

Sand scraper is a kind of equipment used for scraping and grinding the surface of granular materials. Sand scraper is generally composed of scraper with specific geometry and device that can apply force. By applying a given load to the sample surface, the wear or reduction of the material surface can be simulated. Sand scraper is mainly used to study the wear resistance and surface hardness of granular materials.

To sum up, the acid discharge instrument is mainly used to measure the pH value of the solution, while the sand scraper is used to simulate the experiment of scraping and abrasion of the material surface. Their applications and measurement objects are different.