• Hood: Usually made of corrosion-resistant and easy-to-clean materials, such as 304 stainless steel, to ensure durability and cleanliness under long-term use.

• Static Pressure Box: Used to store the filtered air to maintain the balance of air pressure inside the hood.

• Air supply box: responsible for uniformly sending the filtered air into the working area, adopting high efficient equalizing film technology to ensure the uniformity of air speed.

• Filtration system: including primary filter, intermediate filter and high efficiency filter, used to intercept pollutants of different particle sizes to ensure air cleanliness.

• Lighting system: Provide sufficient lighting, usually using UV-free lighting to prevent harm to operators and samples.

• Control system: including touch screen, PLC controller and frequency converter, etc., to realize precise control of the fan, as well as monitoring and management of the working environment.

Every aspect of the system, from material selection to system configuration, is designed to provide a safe, clean and controlled operating environment. These designs not only ensure operator safety, but also ensure the accuracy of experimental data and purity of samples.

• Stainless Steel: The shell and frame of most negative pressure weighing chambers are made of 304 stainless steel, which is ideal for use in cleanroom environments due to its excellent corrosion and antimicrobial resistance.

• Even Flow Membrane: The polymer even flow membrane used on the air supply surface effectively improves the uniformity of the outgoing air and ensures consistent air velocity in the working area, which is essential to prevent cross contamination.

• Filters: High-efficiency filters are central to ensuring air cleanliness, and they are often DOP or PAO tested to ensure that they filter out more than 99.99% of particulate matter.

• Lighting fixtures: Lighting system fixtures are usually of the type that do not emit UV rays to avoid potential harm to operators while meeting illumination requirements.

Negative pressure weighing chambers usually consist of a working area, a return air box, a fan box, an outlet air box and an outer box. The working principle is based on vertical unidirectional airflow design, where the air is pre-treated by primary and intermediate filters, and then further purified by high efficiency filters to achieve the required cleanliness. The purified air is circulated in the working area, and part of it is discharged through the air outlet system to maintain negative pressure in the working area. This design effectively prevents the leakage of indoor pollutants and also avoids the risk of cross-contamination between different medicines.

Options. 

1	Wind Speed Sensor
2	Differential Pressure Sensor
3	converter
4	touchscreens
5	PLC control
6	Polymer homogeneous membrane