| 100% tracability and compliance with ISO 9000 quality requirements. | Batch records may not tie up with actual dosage as flow meter inaccuracy cannot be recorded. |
| Scales are properly calibrated and traceable to national and international standards and tolerances. Batch computers hold a record of what has been weighed ensuring traceable confirmation of the volume dispensed. | Flow meters are not calibrated in the strict compliance sense. Supply companies simply do a check and issue a dosage check document. Although the batch computer holds a record of what has been requested from the flow meter there is physically no confirmation that what was requested is what has been dispensed. |
| Admixtures are pre-weighed then held in the hoppers ensuring rapid discharge with no impact on batch cycle. | Admixtures are batched directly into concrete mix, which could slow batching cycle |
| Admixtures can be dosed at any stage of batching and in multiple dumps – thereby achieving optimal performance. | Admixtures are difficult to batch at certain stages of the batching sequence |
| Calibration is “hands off” and automated and can be executed after every batch if required. | Calibration is cumbersome and messy; the frequency is reduced due to the inconvenience. |
| New Admixtures can be added to the scale simply | New Admixtures require a full admixture line, and possibly an extra controller. |
| Large quantities of admixture (up to 225l) can be dispensed rapidly and accurately into the batch, ensuring optimal dosing and no delays in the batch cycle. | Dispensing large volumes can cause increased inaccuracy, an inability to dispense at optimal time in the batch cycle and delay the batch cycle time. |
| The batching hoppers are continually emptied and cleaned after each batch. | Reliability can be hindered by the efficiency and cleanliness of the pulse meter. |
| The weighing of the liquid ensures an accurate dosage, continuous self calibration maintains accuracy. | To ensure accuracy a second pulse meter or sight glasses is often needed or requested. |
| Target weigh tolerance of 0.01% to 0.05% of volume. | AS1397 allows a tolerance of ±5% or less |
| Each batch is weighed which makes it easy to detect overruns or incorrect dosages. | Difficult to detect overruns or incorrect dosages. |
