Define the question the sample must answer
A qualification sample, a sample from a delivery and a sample taken during a complaint represent different events. Record which event applies and who collected the material. State whether the retained material is intended for identification, comparison testing or another agreed purpose.
Do not assume a small portion represents every package in a shipment. Sampling scope and method should follow the product, receiving plan and agreement. Where representativeness is uncertain, keep that limitation attached to the label.
Keep identity attached to the material
Record manufacturer, product code, lot number, collection date and the associated delivery or trial. Preserve relevant packaging and document references. A sample that can only be identified from someone's memory has limited value for a later disagreement.
Avoid combining material from separate lots into one reference unless an approved procedure explicitly requires it and preserves the necessary information. Separate containers make an unexpected result easier to trace without confusing manufacturing and handling events.
Agree storage and review conditions
Follow the instructions for the exact product and container. Ask what retained-sample conditions are appropriate and how long a comparison is expected to remain meaningful. There is no universal retention period that can be assumed for all PAM products.
Record opening, damage, moisture exposure or other relevant events. A sealed-looking package does not prove unchanged properties. Review the reference condition before using it to challenge a newly delivered lot.
Use the reference with a defined method
Prepare the retained and questioned materials with controlled, documented procedures. Record the same feed and measurement conditions when the objective is an application comparison. Storage-related changes can otherwise be mistaken for manufacturing differences.
Connect the result with measurement reconciliation and the complaint record. Preserve observations that weaken as well as support a proposed explanation.