Weigh Batching vs Volumetric Batching

HMT Admix – Multi Compartment Chemical Admixture Scales ensure the highest degree of accuracy, reliability and flexibility giving you complete confidence and certainty that admixture dosages are correct.

Weigh Batching	Volumetric Batching
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.