The ST1 Safety Weighing Enclosure is a sophisticated system designed to protect users and the environment from hazardous aerosols and dust during weighing and small-scale handling of substances. It operates with a low-turbulence, horizontal airflow across the entire work area, ensuring optimal interaction between the scale and the enclosure. The system's design prevents the leakage of hazardous substances into the surrounding room air through convection and diffusion of incoming air and the working opening.
Function Description:
The ST1 series is designed as a closed system with an integrated extraction system. Airflow is continuously maintained by a motor-driven filter housing, ensuring a constant air volume (CAV) through the working opening. This prevents exposures from escaping and endangering the user. The system is equipped with an H14 HEPA filtration system, which has a retention rate of at least 99.995% and is suitable for an operating time of up to 3 years. For enhanced safety, a visual and acoustic alarm is triggered if the airflow falls below a predefined limit, such as when the front flap is opened. A unique feature is the monitoring of airflow with a separate sensor located outside the work opening, providing real-time conditions at the access point.
The enclosure is suitable for personal protection in accordance with EN 14175-3 for fume cupboards and complies with the ASHRAE 110 standard. It has been tested with surrogate substances according to EN 689 and ISPE guidelines, demonstrating an exposure control limit (ECL) of less than 20 ng/m³ for weighing and small-scale handling of hazardous substances up to 1g.
Usage Features:
The ST1 safety weighing enclosure is intended for weighing and manipulating hazardous substances that pose a risk upon release. It is crucial to operate the enclosure in an area free from explosive atmospheres. When cleaning with flammable solvents, the ventilation systems must be switched on.
Ergonomic design is a key aspect, featuring an ergonomically shaped arm bar that allows users to lean forward comfortably while working. The special frame construction of the work surface provides protection against leaking liquids, retaining small quantities within the enclosure. The double bag waste system (optional) facilitates contamination-free disposal of waste.
Important Technical Specifications:
The ST1 series is available in three different widths: 900mm, 1200mm, and 1500mm.
- Dimensions (Weighing Enclosure):
- ST1-900: 896 x 694 x 763 mm (W x D x H)
- ST1-1200: 1196 x 694 x 763 mm (W x D x H)
- ST1-1500: 1496 x 694 x 763 mm (W x D x H)
- Weight (without packaging):
- ST1-900: 61 kg
- ST1-1200: 81 kg
- ST1-1500: 101 kg
- Materials:
- Base plate: Ceramic
- Profiles (front, back, left, right): 1.4301, <0.6 µm ground
- Arm bar: 1.4301, <0.6 µm ground
- Side wall (left, right), Cover, Flap: PMMA (acrylic)
- Baffle, Plenum: Polystyrene
- Work surface: Chemical-resistant ceramic
- Filtration System:
- HEPA filter (H14): Retention rate of at least 99.995%. Available in single or two-layer configurations.
- Optional Carbon filter: Retention capacity of approx. 0.5 kg of solvent vapours.
- Airflow:
- Inflow velocity: 0.4 m/s (standard setting)
- Constant Air Volume (CAV) at the outlet of the filtration unit:
- ST1-900: 177 m³/h
- ST1-1200: 243 m³/h
- ST1-1500: 310 m³/h
- Power Consumption (System):
- ST1-900: 0.38 kWh
- ST1-1200: 0.5 kWh
- ST1-1500: 0.63 kWh
- Alarm System:
- Monitors incoming air velocity via a pressure difference sensor.
- Visual and acoustic warnings for low flow velocities.
- Operating speed at access opening: 0.4 m/s.
- Components: Display (410x160x120 mm), Electronics box (410x160x120 mm), Sensor (53x39x23 mm).
- Power consumption: 100 W (alarm system), 24 W (LED lamp), 600 W (fan unit).
- Voltage: 110-230 V (alarm system, fan unit), 24V DC (LED lamp).
- Frequency: 50/60 Hz.
- Optional Accessories: Silencer box, in-line silencer, additional solvent filter, electrostatic discharge systems (antistatic bar, point electrode), double bag waste system, printer table.
Maintenance Features:
Regular maintenance is crucial for safe and contamination-free operation.
- Daily: Visual inspection of the enclosure, arm bar, ventilation hoses, and filter housing. Cleaning and decontamination of the base plate and front flap.
- Monthly: Visual inspection of electrical connections, ventilation hoses, cable cover plates, screws on the air-collecting chamber, and waste system. Functional test of the alarm system (sensor test, smoke test). Basic cleaning of the interior, excluding the rear wall.
- Annually: Basic cleaning of the entire enclosure, including the rear wall. Functional tests including checking inflow velocity, calibrating the alarm system, and checking filter retention rate (DOP test).
- Filter Change: HEPA filters should be replaced every 3 years (manufacturer's recommendation). Carbon filters should be changed at least once a year due to limited adsorption capacity. Filter changes and adjustments to inflow velocity must only be carried out by qualified personnel (a1-envirosciences technicians or authorised personnel). A DOP test is required after each HEPA filter change.
- Cleaning Agents: Ceramic parts are resistant to conventional cleaning agents. Acrylic parts should be cleaned with aqueous or ethanol-containing solutions (up to 30%). Acetone or strong solvents are not recommended for acrylic surfaces. Brushes with polyamide bristles are suitable for cleaning discharge electrodes.
- Malfunction: In case of an alarm (e.g., "Airflow Fail"), users should keep hands inside the enclosure, check for power failure, and ensure no objects obstruct the airflow sensors. If the issue persists, contact a1-envirosciences service.
- Decommissioning and Disposal: Dismantling and disposal of the enclosure should ideally be performed by a1-envirosciences GmbH due to potential contamination risks. If done independently, the enclosure must be thoroughly decontaminated, and hoses should not be removed. The entire unit, including the filter, should be hermetically packed and disposed of according to local waste regulations.
Need help?
To Next Page
General