Gravimetric Feeder vs. Volumetric Feeder: Key Differences, Applications, and How to Choose
Choosing the right feeder system is critical for maintaining precision and consistency in dosing operations. Gravimetric (loss-in-weight) feeders and volumetric feeders each offer unique advantages.
This guide breaks down the key differences, ideal use cases, and how High Dream’s advanced Loss-in-Weight Feeders help manufacturers achieve long-term stability and precise scale production.
What Is a Gravimetric Feeder (Loss-in-Weight)?
A gravimetric feeder—or loss-in-weight feeder—measures the exact weight of material dispensed and adjusts in real time to maintain a set rate. These closed-loop systems detect weight loss through load cells and automatically adjust the screw speed by slowing down or speeding up to maintain feeding accuracy.
A loss-in-weight feeder continuously monitors hopper weight loss and automatically adjusts the real-time feeding rate, ensuring gravimetric accuracy without the need for manual intervention.
How Gravimetric Feeders Ensure Accurate Feeding
- Real-time feedback system ensures precise and consistent feeding
- Adapts to bulk density variations automatically
- Ideal for high-precision processes (e.g., ±1% accuracy or better)
Typical industries served include plastics (e.g., extrusion, colorant dosing), food production, chemicals, and pharmaceuticals—sectors where precision, consistency, and traceability are essential.
Types by High Dream
| Feeder Type | Description & Typical Application |
| Micro Flow Single Screw Type | Ideal for very low flow rates (0.1-5 L/h), this compact single screw feeder suits micro-dosing of powders and granules with high precision. |
| Micro Flow Twin Screw Type | Offers enhanced consistency using dual screws—perfect for tiny doses (0.5-5L/h) where material flow is prone to variation. |
| Twin Screw Type | Specially designed for granular or poor-flowing materials, improving accuracy and stability in medium-volume production. |
| Single Screw Type | Offers both solid and hollow screw options to meet high-volume production needs for granules and free-flowing materials (e.g. plastic pellets, gravel, flake activated carbon). |
| Single Serve drive Feeder | Equipped with a single servo-driven screw for precise speed control, explosion-proof design, and IP65 dust and water resistance. |
| Flexible-hopper Padding Feeder | The irregular hopper design effectively prevents material bridging, making it suitable for powders or free-flowing materials. |
| Upgrade Vibratory Type | Enhanced vibration model delivers stable signals with multiple flow options (up to 10,000 L/h), suitable for fragile materials like flakes and glass fibers. |
| Vibratory Type | Designed for fragile materials such as flakes and glass fibers, providing both continuous and batch weighing options. |
| Liquid Type | Designed for liquid dosing with pump options and thermal jackets; mobile for flexible industrial setups. |
| Large-flow Twin Screw Feeder | Feed rates up to 1 ton/hour with explosion-proof and food-grade options; tool-free disassembly supported. |
| Large-flow Single Screw Type | Ideal for high-speed, high-precision feeding, with throughput up to 1 ton/hour. |
| Blender Type I & Blender Type II | Specifically designed for infant formula dosing and precise granule feeding, offering customizable configurations and easy installation and maintenance. |
| Colorant Feeder | Ensures precise dosing of masterbatch and recycled plastics, minimizing loss and waste of color granules. |
| Belt Type I & Belt Type II | Designed for large and fragile materials (e.g. potato chips, nuts, fiberglass), offering ±1% accuracy and easy cleaning and maintenance. |
What Is a Volumetric Feeder?
A volumetric feeder can only adjust screw speed manually to deliver material at a fixed rate. Relying on mechanical measurement without real-time feedback, it cannot accurately determine actual flow, resulting in larger errors. While the structure is simpler and the cost is lower, it typically requires frequent manual recalibration and struggles to maintain consistency when material conditions change.
Variants include:
- Volumetric screw feeders
- Metering systems for powders and granules
They suit applications with stable flow materials and lower precision needs.
Gravimetric Feeder vs. Volumetric Feeder: Side-by-Side Comparison
| Feature Gravimetric | Feeder (Loss-in-Weight) | Volumetric Feeder |
| Accuracy | High (real-time weight control) | Moderate (manual calibration) |
| Material density handling | Automatic compensation | Fixed rate; density changes affect flow |
| Cost | Higher upfront, lower long-term cost | Low initial investment |
| Applications | Critical dosing, variable materials | Simple, homogeneous materials |
| Waste & ROI | Higher initial, better ROI | Lower cost, more waste risk |
This comparison chart offers a quick reference for selecting the most appropriate feeder based on performance, complexity, and operational cost.
Choosing Between Gravimetric and Volumetric Feeding Systems: 5 Key Factors
Choosing the right feeder depends on your material characteristics, precision requirements, and production goals. Here’s how to make an informed decision:
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Material Characteristics
For powders or granules that vary in bulk density or are prone to bridging, opt for a gravimetric feeder. These loss-in-weight systems continuously measure weight, automatically adjusting feed rates–ideal for inconsistent or critical materials. Volumetric feeders work well for consistent, free-flowing pellets or granules.
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Accuracy & Control Requirements
Gravimetric feeders deliver high dosing precision using closed-loop weight control, often within ±1%—perfect for formula-critical applications. In contrast, volumetric feeders rely on screw speed settings and manual calibration, often falling short with variable materials.
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Industry Needs
Different industries have distinct feeder requirements:
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Food and Pharma
: Require hygienic designs, recipe traceability, and integration with automated systems. -
Chemicals and Plastics
: Need robustness against abrasive or variable materials—gravimetric feeders offer consistent ratios. -
Energy and Construction
: Often use voluminous, consistent bulk materials; volumetric systems may be adequate.
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Production Volume & Throughput
High-output processes such as extrusion and injection molding benefit from gravimetric feeders, which provide real-time accuracy control and instantly adjust to maintain a stable flow while avoiding material waste. Volumetric feeders, on the other hand, are more suitable for low-output applications or less critical materials, but they struggle to ensure consistent discharge and recipe stability, making it difficult to meet the real-time feeding demands of downstream equipment.
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Integration & Automation Readiness
If your production line demands full automation, batch traceability, or frequent material changes, gravimetric feeders support recipe control and remote monitoring via PLC or Internet. Volumetric feeders lack such flexibility and often require manual intervention.
High Dream’s Gravimetric (Loss-in Weight) Feeder Solutions
High Dream offers advanced loss-in-weight feeder models perfect for precision dosing:
- Modular design with customizable screws and hopper sizes
- High accuracy, adaptable for powders, granules, regrind
- Touchscreen controls, recipe storage, and optional connectivity
- Self-calibrating systems equipped with load cell weight monitoring
- Assistance tech, including vibration aids, to ensure steady flow
High Dream's Loss-in-Weight Feeders can also be integrated into customized production lines per your requirements—delivering turnkey solutions that combine multiple units into a coordinated manufacturing process.
Our feeders reduce waste, maintain accurate ratios, and scale with your production needs. They offer key advantages for your business: improved product stability, enhanced traceability, and ROI within months.
Finding the Right Feeder for Your Needs
- Choose gravimetric (loss-in-weight) for demanding precision, variable materials, and long-term savings.
- Choose volumetric if your process involves stable materials and low-cost simplicity.
High Dream's gravimetric feeders offer high accuracy, ease-of-use, and industry flexibility—ideal for complex dosing processes in food, pharmaceutical, chemical, and plastic applications.
Ready to optimize your feeding system? Contact High Dream to explore your options or request a demo. Visit our Loss-in-Weight Feeder product page and discover the ideal feeder for your process.