Lưu ý: Bản dịch của mục này hiện đang được kiểm tra chất lượng, vì vậy một số nội dung tạm thời chỉ hiển thị bằng tiếng Anh.
Mục từ này chưa được dịch sang ngôn ngữ của bạn, vì vậy nội dung gốc được hiển thị bên dưới.
ppm
This term is a technical abbreviation used primarily in chemistry, environmental science, and engineering to quantify trace concentrations. It provides a dimensionless ratio that allows scientists to describe very small amounts of a solute or pollutant without needing to specify the mass or volume of the total mixture.
As a unit of measurement, it functions as an uncountable noun in technical writing. It is typically used as a label for a numerical value (e.g., 50 ppm) rather than as a countable object. Because it represents a ratio, it does not take a plural form in standard scientific notation.
Ý nghĩa
Ví dụ
The sensor detected a chlorine concentration of 5 ppm in the water.
The air quality monitor shows the ozone level is currently 40 ppm.
We need to reduce the sulfur content to under 15 ppm to meet the new regulations.
The lab report indicates that the sample contains 200 ppm of sodium.
I wonder if the ppm of carbon monoxide in this garage is dangerous.
The dissolved oxygen levels are measured in ppm for this specific aquatic study.
The technician noted that the ppm reading was fluctuating wildly.