(1) Instantaneous flow rate:

Describes the volume of fluid passing through a pipe or fluid medium at a specific moment. In short, instantaneous flow focuses on the fluid flow at a certain moment.

Instantaneous flow is usually represented by the symbol Q, and its unit is the volume unit divided by the time unit, such as cubic meters per second (m³/s) or liters per second (L/s).

(2) Accumulated flow, also known as "flow accumulation":

It refers to the cumulative value of the instantaneous flow rate of on-site liquids, gases, etc. through a certain pipeline within a certain period of time. Simply put, it represents the total amount of fluid (total volume or total mass) flowing through a pipe or a cross-section in a pipe during a certain period of time.

This total amount is equal to the integral of flow over time within this period, and its unit can be cm³, L, m³ or g, kg, t, etc.

In practical applications, general field instruments only record instantaneous flow, while modern algorithms and technologies can accumulate the sum of all flows within 1 hour, 1 day, 1 week or even longer. Through the calculation of accumulated flow, It can achieve the purpose of controlling the amount of flow adjustment in each period of time.

(3) Please note that instantaneous flow and cumulative flow are two different ways of expressing flow. Instantaneous traffic focuses on the traffic situation at a certain moment, while cumulative traffic is the sum of traffic over a period of time.