| Single-screw feeder | Free-flowing powders, pellets, and granules with reasonably consistent bulk density. | Mount the weigh hopper and feeder on a stable support. Use flexible inlet and discharge connections so pipework does not place force on the weighing assembly. Provide access for screw removal and cleaning. | Check the empty-weight zero, then verify the weighing system with suitable traceable test weights. Confirm feed rate by collecting and weighing material over a measured period; test at the intended operating range. | Inspect the screw, trough, seals, and bearings for wear or buildup. Clean product-contact surfaces and check that connections remain flexible and free of material bridging. | A common choice for general-purpose solids. Performance depends on screw geometry, material flow properties, and the selected operating range. |
| Twin-screw feeder | Cohesive, sticky, or difficult-to-flow powders; some recipes that benefit from more positive material movement. | Allow room to remove both screws and access the feed throat. Isolate the weighing assembly from vibration and avoid rigid connections that can interfere with load-cell readings. | Perform zero and span checks with appropriate traceable weights. Verify actual delivery by timed collection at representative rates and material conditions, including after screw changes. | Check both screws for wear, alignment, and buildup. Inspect seals and drive components, and clean the trough and feed zone according to the material and hygiene requirements. | Can improve handling of challenging powders, but requires careful screw selection and cleaning access. It is not automatically suitable for every cohesive material. |
| Agitator-assisted screw feeder | Powders that tend to bridge, rat-hole, or feed inconsistently from a hopper. | Install the agitator and hopper so their movement does not transmit unwanted forces to the scale. Confirm safe access to moving parts and follow the equipment maker’s guarding requirements. | Calibrate the weighing system with the agitator in its normal operating configuration. Verify material output over a timed interval, since agitation can affect bulk density and flow. | Inspect agitator arms, clearances, seals, and drive components. Remove accumulated material and check for wear that could change mixing action or create uneven feeding. | Useful where hopper flow is the limiting factor. Agitation should be matched to the material; excessive action can damage fragile particles or change the feed behavior. |
| Micro-screw feeder | Small quantities of powders, pigments, additives, and other ingredients requiring low-rate dosing. | Use a rigid, level mounting surface and protect the weighing assembly from drafts, vibration, and contact with nearby equipment. Ensure the discharge does not pull on the feeder. | Use test weights appropriate to the scale capacity and resolution. Verify delivery with a sufficiently sensitive balance and a collection time long enough to measure the target rate reliably. | Clean small feed passages carefully and inspect the screw and outlet for residue or blockage. Recheck zero after cleaning or any adjustment to the feeder assembly. | Suitable for low-rate applications, but achievable performance depends on scale resolution, material consistency, environmental stability, and the required dosing rate. |
| Vibratory-tray feeder | Free-flowing granules, pellets, flakes, and fragile solids that may be damaged by screw action. | Provide vibration isolation between the feeder and the weighing frame. Keep the tray discharge clear and prevent surrounding structures or chutes from touching the weighed assembly. | Check zero and span with traceable weights. Verify feed rate by timed collection at the intended vibration setting and material depth; repeat if tray amplitude or material changes. | Inspect the tray, spring or isolation elements, drive, and fasteners. Remove dust and product buildup, and check for changes in vibration or unusual noise. | Gentle metering can suit fragile products. Feed behavior is affected by particle shape, tray condition, vibration settings, and the installation’s vibration isolation. |
| Loss-in-weight weigh-belt feeder | Granules, flakes, pellets, and other bulk solids that can be conveyed in a stable layer on a belt. | Keep the belt frame level and free from external contact. Provide belt-tracking adjustment, access for cleaning, and suitable transitions that do not load the weighing frame. | Verify scale zero and span with appropriate test weights. Check belt speed and confirm mass delivery with a timed collection or independent mass measurement at representative operating conditions. | Check belt tracking, tension, splices, rollers, and scrapers. Remove buildup and inspect for belt wear, material carryback, and changes in drive or roller condition. | Best when the material forms a consistent belt layer. Very fine, sticky, or irregular material may require a different feeding mechanism or additional conditioning. |
| Loss-in-weight liquid pump system | Liquids and some pumpable mixtures, using a supply tank or vessel mounted on a weighing system. | Support the tank and pump without transmitting pipe stress to the scale. Use flexible hose connections, secure the lines against movement, and account for pulsation and vibration from the pump. | Check the weighing system with suitable traceable weights. Verify delivered mass over a measured period using a collection vessel and independent weighing; account for fluid temperature and operating conditions. | Inspect the pump, hoses, seals, and fittings for leaks, wear, and blockage. Flush or clean product-contact parts as required, and check connections after maintenance. | Choose a pump compatible with the liquid’s viscosity, solids content, temperature, and chemical properties. Confirm that the weighing setup remains stable during pumping. |