Dispensing Booth
Dispensing Booth | Sampling Booth | Weighing Booth | Downflow Booth
The dispensing booth(also known as weighing booth, sampling booth or downflow booth) is a localized air purification equipment used for sampling, weighing and analysis. It is widely used in pharmaceutical, microbiological research and scientific experiments or other fields.
It provides vertical one-way airflow, which can generates negative pressure in working area. It avoids the spread of dust from the working area to the production area, prevents cross contamination, ensuring the cleanliness in the working area is always at a high level.
As one of leading dispensing booths manufacturers in China, we can customize based on special requirements. Please send us your specifications to tailor your weighing booth solutions.
Product Specifications
| Model | DB-1500 | DB-1900 | DB-2500 |
| External Size(W*D*H) mm | 1500*1500*2600 | 1900*2400*2600 | 2500*3000*2600 |
| Internal Size(W*D*H) mm | 1400*1000*2000 | 1800*1800*2000 | 2400*2400*2000 |
| Main Body Material | 304 Stainless Steel | ||
| Purification | G4 | G4 | G4 |
| F8 | F8 | F8 | |
| H14 | H14 | H14 | |
| Purification Level | ISO 5(Class 100), Class A |
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| Purification Efficiency | 99.995% at 0.3μm | ||
| Air Speed | 0.36-0.54m/s, Average Speed 0.45m/s | ||
| Touch Screen | Siemens or Others | ||
| PLC | Siemens or Others | ||
| Pressure Gauge | Dwyer or Others | ||
| Noise(db) | ≤75 | ||
| Customized design for size, material, and other specifications is available, click the button below for asking a tailored solution. | |||
Dispensing Booth Structure
1. Exhaust Regulator 2. Air Distribution Plate 3. Lights 4. Top Housing 5. Air Guide Plate 6. Fan 7. Fan Housing 8. High Efficiency Filter 9. Medium Efficiency Filter 10. Primary Efficiency Filter 11. Bottom Housing 12. Control Panel 13. Enclosure System
Optional Functions
- Individual control of power distribution cabinet
- LCD screen/touch screen control
- Alarm for abnormal air speed, pressure difference, temperature, humidity, etc.
- USB interface for data printing
- Temperature and humidity adjustment
- Dust particles and floating bacteria detection
- PLC automatic control for constant temperature and humidity
- Temperature and humidity display
Weighing Booth Manufacturer-The Complete FAQ Guide
Learn more about the weighing booth with this guide. We prepare some questions and answers for you.
- What Is A Cleanroom Weighing Booth?
- What Are the Primary Functions of A Weighing Booth?
- What Is the Working Principle of A Negative Pressure Weighing Booth?
- What Are the Features of KINROM Weighing Booths?
- When Should Filters in A Weighing Booth Be Replaced?
- What Is the Difference Between the Negative Pressure Weighing Booth and Clean Bench?
- How Is A Weighing Booth Installed?
What Is A Cleanroom Weighing Booth?
A cleanroom weighing booth, also known as a dispensing booth, downflow booth or sampling booth, is a self-contained, localized air purification unit. It is engineered to provide a vertical unidirectional airflow within a controlled environment, creating a defined negative pressure at the work zone. This configuration prevents cross-contamination by partially recirculating purified air and partially exhausting it, thereby ensuring a high-integrity workspace for critical weighing operations.
Picture 1 Cleanroom Weighing Booth
What Are the Primary Functions of A Weighing Booth?
The primary functions of a weighing booth can be systematically summarized into three core aspects, designed to provide a safe, reliable, and controlled local environment for precision weighing:
Product/Material Protection:
It creates a high-cleanliness operating environment through vertical unidirectional (laminar) airflow and an enclosed design. This effectively isolates external contaminants, prevents cross-contamination of materials during weighing, and minimizes air turbulence to ensure the stability of high-precision balances, thereby guaranteeing absolute weighing accuracy and product quality.
Operator Safety Protection:
Through negative pressure containment and directional airflow, it establishes an air barrier between the operator and the material. It effectively controls and captures hazardous dust or aerosols generated during weighing, preventing the operator from inhaling harmful substances via intake through the front sash or work area, ensuring occupational health and safety.
Environmental Safety Containment:
The built-in high-efficiency filtration system (e.g., HEPA filters) reliably captures and contains hazardous particles generated during operation. The filtered clean air is partially recirculated internally and partially safely exhausted, preventing the escape of hazardous substances into the external workshop or atmosphere, thus protecting the surrounding environment.
What Is the Working Principle of A Negative Pressure Weighing Booth?
The negative pressure weighing booth operates on a vertical unidirectional airflow principle designed to maintain containment. As illustrated in the diagram below, the airflow follows a top-down, side-return pattern.
Picture 2 Weighing Booth Working Principle
The air is supplied vertically from the top and purified by passing through a HEPA filter, flowing downward over the work area. This laminar airflow directs any airborne particles generated during weighing operations toward the side or bottom air inlets. The contaminated air then passes through a multi-stage filtration system—typically including primary, intermediate filters—for preliminary and secondary filtration.
After pre-filtration, the air is drawn by the fan into the HEPA filter plenum. Here, the airflow is split: One portion(around 90%) is recirculated through the HEPA filter back into the work zone, the remaining portion is exhausted through an additional exhaust filter.
This configuration creates and maintains a relative negative pressure inside the booth compared to the surrounding environment. Typically, most of the airflow is recirculated within the booth, with only a small percentage being exhausted externally. This balanced airflow design ensures both energy efficiency and the maintenance of a localized negative pressure environment, effectively preventing the escape of hazardous materials while providing a clean workspace for sensitive weighing operations.
What Are the Features of KINROM Weighing Booths?
KINROM Weighing Booths integrate advanced engineering and user-centric design to provide superior containment, operational efficiency, and regulatory compliance for critical weighing applications. Below are our key features:
1. Hygienic & Modular Design
Constructed from high-grade, sanitary stainless steel with a modular structure. This compact design is easy to clean, minimizes leakage risks, and facilitates easy movement and on-site installation within the facility.
2. Built-in PAO Test Port
Equipped with a dedicated PAO test port for straightforward and reliable integrity testing of the HEPA filter, ensuring optimal performance and safe, leak-free operation.
3. Multi-Stage Filtration & Airflow
Features a triple filtration system (Primary, Medium, and HEPA) that self-circulates air within the weighing zone. The HEPA filter removes 99.99% of particles ≥0.3μm, guaranteeing a clean environment that complies with pharmaceutical GMP requirements. Laminar airflow is ensured by an air diffuser membrane for uniform downflow.
4. Intelligent PLC Control & Monitoring
An automated PLC control system, managed via a user-friendly touchscreen HMI, dynamically maintains critical parameters. It includes differential pressure monitoring for filter status and system self-correction with alarms for operational deviations.
5. Stable & Quiet Operation
Powered by a maintenance-free, variable-frequency external rotor centrifugal fan. This ensures consistent airflow velocity while maintaining low noise levels during operation (≤70 dB).
6. Ergonomic & Safe Design
Smooth, Coved Interiors: Rounded corners and seamless surfaces prevent dust accumulation and enable easy cleaning.
PVC Strip Curtain: Creates an effective air barrier to maintain pressure differentials.
Adequate Illumination & UV/Option: Provides >300 Lux lighting at 1-meter height, with optional UV or ozone sterilization for decontamination.
7. Customization & Support
We offer flexible customization to meet specific client needs, including optional features and specialized models for demanding environments, backed by our dedicated after-sales support.
When Should Filters in A Weighing Booth Be Replaced?
Filter replacement is critical for maintaining the performance and safety of your weighing booth. The replacement schedule varies by filter type and is determined by both scheduled maintenance and performance indicators.
1. Primary Efficiency Filters
Frequency: Typically every 1-3 months.
Indicator: Visual inspection shows significant dust loading or discoloration. A marked increase in the differential pressure across the filter assembly is a key signal for replacement.
2. Medium Efficiency Filters
Frequency: Typically every 6-12 months.
Indicator: Replacement is often tied to a sustained increase in system pressure drop, indicating reduced airflow due to filter loading.
3. HEPA Filters (Critical)
HEPA filters are not replaced on a fixed schedule but based on the following conditions:
Primary Indicator:
The differential pressure across the HEPA filter reaches the manufacturer’s specified final resistance value.
Performance Indicators:
Inability to Maintain Airflow: The fan operates at maximum capacity but cannot restore the required face velocity (e.g., 0.45 m/s) in the work zone.
Failed Integrity Test: A routine PAO/DOP test detects leaks that cannot be sealed, indicating a compromised filter.
Physical Damage: Any visible damage to the filter media, seals, or housing.
What Is the Difference Between the Negative Pressure Weighing Booth and Clean Bench?
Negative pressure weighing booths and clean benches are fundamentally different in both design and function, with their core distinctions stemming from their completely different operational purposes.
The primary mission of a clean bench is product protection. It achieves this by creating and maintaining a positive pressure environment inside the unit. The fan draws air through a high-efficiency particulate air (HEPA) filter, creating a clean, unidirectional airflow that continuously blows outward, toward the operator. This establishes a particle-free zone over the work surface, ensuring that the samples or products inside are protected from external contamination. Consequently, it is only suitable for handling materials that are sensitive to contamination but are inherently non-hazardous, such as cell cultures, dispensing sterile reagents, or assembling precision electronic components.
In contrast, the core mission of a negative pressure weighing booth is safety protection. Its design focus is on safeguarding the operator and the external environment from hazardous substances handled inside. It achieves this through an exhaust system that actively creates a negative pressure state inside the booth, ensuring that the airflow direction is always inward. This design effectively contains any hazardous dust generated during weighing operations within the unit, where it is safely captured by HEPA filtration before being exhausted, preventing operator inhalation or the dispersion of contaminants into the surrounding room. Therefore, it is essential for handling highly active, toxic, or hazardous powders, such as active pharmaceutical ingredients (APIs) or cytotoxic drugs.
The fundamental differences between the two devices are summarized in the table below:
| Comparison Dimension | Weighing Booth | Clean Bench |
| Primary Objective | Safety Protection | Cleanliness Assurance |
| Protection Target | Operator, External Environment, Product | Only the product |
| Pressure Status | Negative Pressure | Positive Pressure |
| Airflow Direction | Inward suction, containing contaminants inside | Outward blow, flushing the work surface with clean air |
Table 1 Difference between Weighing Booth and Clean Bench
