How many samples should be sent to a test lab, and what should be recorded for each?

Main answer · Wecent Editorial Team

Short answer: Send the number of units the lab lists in writing, with a few spares, and give each unit a unique ID. Record its build state, photos, the test it is meant for and the date sent, and keep identical reference units at your site. Good records let you trace any result to a specific unit and prove what was tested.

How many

Ask the lab for a written list of units per test. Because some tests destroy units and others run in parallel, the lab decides. Add a small number of spares. Keep at least one identical reference unit for yourself.

Give every unit an ID

Label each unit with a unique number on the product or a durable tag, and keep a table that links the number to: – Model, variant and plug type. – Build date and production batch or sample stage. – Bill of materials version. – Firmware version, if any. – Special notes, such as whether the unit has a prototype part.

Photos

Photograph each unit from several sides, including the label, before shipping. Photos prove the state at the time and help if a unit arrives damaged.

Plan the tests

Record which test or group of tests each unit is for, as agreed with the lab. This prevents units being used for the wrong purpose.

Shipping and custody

Record the carrier, tracking number, date sent and date received, and ask the lab to confirm receipt and condition. Keep copies of the sample list signed by the lab.

After testing

Ask the lab what happens to the units. Many labs keep them for a period. Ask for return of units that are not destroyed, and for photos of failures.

Link to the report

The report should list the sample IDs. Check that the IDs in the report match yours.

Quick summary

Get the lab’s list, ID every unit, photograph and record the build state, track shipping and match the report.

Example sample table

Unit 01: model 65A-US, black, sample stage three, bill of materials version two, firmware not applicable, photo set saved, intended for safety tests, shipped on a given date by tracked courier. One row per unit, saved with the lab’s signed receipt, makes the file easy to audit later.

Where this answer says to confirm with Wecent, the detail is not published on the product page and has to come from the datasheet or the factory. General facts come from the regulators, standards bodies or device makers named in the text.