How to record net weight at an RVM collection handover

To report how much material was collected from a reverse vending machine (RVM), record the loaded container weight and the tare for the same container setup. Subtract the tare once to get the net weight. If the scale or receiver already supplies a net reading, record it as net. Keep the source ticket with the batch so the next person can see what was weighed.

What do gross, tare and net mean at collection?

• Gross is the weight of the load as weighed, including the tote and any liner, lid or other accessories that were on the scale.
• Tare is the weight attributable to the empty tote and those same accessories.
• Net is the weight left after accounting for that tare. Net weight includes everything left in the batch, such as residual liquid or contaminants. Any claim about dry or sorted material needs a separate measurement.

In this example, an 18 kg loaded tote and a 3 kg matching empty tote yield 15 kg of collected material. If the replacement tote weighs 4 kg, the same gross reading yields 14 kg. Identify the tote before reusing a stored tare, especially after a liner or lid changes.

What should an operator put on the handover record?

1. Identify the machine, batch, material stream and tote. If several bags go on one ticket, list their batch IDs and treat the ticket as a combined weight.
2. Record the weighing time, location, unit and ticket reference. Keep the displayed value and mark it as gross, tare or net. When using a stored tare, record where that tare came from.
3. Link the receiver’s ticket when it arrives. If a tare or batch reference is missing, mark the net figure as pending and assign someone to resolve it. Leave missing weights blank so a report can distinguish them from measured zeroes.

What if the receiver’s figure differs from the site’s?

Check the batch IDs, weighing points and units first. If the receiver weighed three bags together, compare their ticket with the combined site record. Check whether either reading includes the tote or liner. Small differences can also arise when the scale displays gross, tare and net at rounded precision. Keep the original figures and record the reason for any correction, along with the source used.

Machine acceptance logs answer a separate question about how many items the RVM accepted. Keep counts and weights in separate fields so operators can trace each back to its source. See the collection handover guide for the rest of the batch record and the RVM pilot evaluation guide for how to use handover data in a pilot review.