I. Introduction to the Negative Pressure Weighing Hood:
The negative pressure weighing hood is a specialized and dedicated workspace specifically designed for sampling, weighing, analysis, etc. industries. It can prevent dust and particles in the working area from spreading to the outside of the operation area, ensuring that operators do not inhale the items being operated on. It is a dedicated purification equipment for controlling dust飞扬. The indoor air passes through the primary filter， the intermediate filter， and is then pressurized by the centrifugal fan into the static pressure box. After passing through the high-efficiency filter， it is blown out from the air flow diffusion supply unit at the outlet surface. The clean air flows through the working area at a uniform cross-sectional wind speed， thus forming a highly clean working environment. The operation area of the central weighing chamber is maintained in a negative pressure state， and 10% of the circulating air is discharged. The air in the weighing chamber undergoes a three-level filtration system (the high-efficiency filter removes 99.99% of particles ≥ 0.3 μm and all dust above this size) for self-circulation.

II. Characteristics of the Weighing Hood Produced by Our Company：
1. Modular assembly without being constrained by too much space.
2. Can be externally connected with a wind speed sensor to achieve constant wind speed.
3. Equipped with sound and light alarm， error alarm， and emergency stop functions to ensure timely resolution of error issues.

III. Selection of Control Modes：
1. Frequency converter control (wind speed adjustable)
2. PLC， frequency converter， touch screen control， sensor controller (constant wind speed， touch control)
3. HEPA， DOP test port

IV. Reference Parameters： The size of the weighing chamber can be customized， as well as the accessory functions and control modes.