Does a camera need a manual sampling check?

The MAPA rule on sampling checks is question 34, and it covers electronic candling equipment. A surface camera is not electronic candling, so that rule does not apply to it. Using the same check design is good practice for verifying the camera's results and for showing an auditor how they were validated.

How often should the check run?

This guide gives no number. Frequency is the company's decision, must be justified in the self-control programme, and should be reviewed when the line or the equipment changes. It must be written down before the checks begin, so the record proves the procedure was followed.

Does a manual check prove that the camera sees inside the egg?

No. A sampling check only confirms what the equipment can see. A surface camera does not see the air cell, the yolk or hairline cracks, so sampling cannot validate those items. For the inside of the egg, the reference method remains candling.

Guide · Running the line

How do you run a manual sampling check on candling equipment?

A manual sampling check is a verification, done by people, of some of the eggs the equipment has already graded. When MAPA requires one for electronic candling, it must be validated and described in the self-control programme, with its frequency, evaluation method and record form. A surface camera is not electronic candling, but the same design is good practice for checking its results.

Updated October 9, 2026 · 5 min read

What is a manual sampling check?

It is a check done by people on some of the eggs the equipment has already graded. Each person grades the same eggs by their own criteria, without seeing the class the equipment gave, and the two answers are compared. When the disagreement goes beyond the limit the company sets, the equipment is adjusted before it is trusted again.

For electronic candling, the check is a condition of the rule. MAPA accepts electronic equipment with results equivalent to traditional candling, provided a manual check by a validated sampling system is in place (question 34, which refers to § 4 of art. 26 of Ordinance 612). The full rule is in electronic candling under Ordinance 612.

What must the self-control programme describe?

MAPA asks the company to describe in its self-control programme the frequency of the check, the evaluation method and the record form. Without that written down, the check is a good intention, not evidence an audit can verify.

Frequency is the company's decision and should be justified in the programme itself, based on line volume and how stable the equipment is. This guide gives no number, because it depends on your line and on what your validation shows. What matters is that the frequency is written down before the checks start.

How do you choose the eggs for the sample?

The sample should represent the line, not just the start of the shift. Pick eggs from different times in the shift and from different points on the conveyor, and include eggs from every class the equipment produces, not only the clean ones.

Avoid picking only the easy eggs. A sample without the hard cases measures how easy the sample was, not how accurate the equipment is. Grade the eggs blind, without the person knowing the class the equipment gave, so the result is not influenced.

How do you evaluate and record each check?

The evaluation compares, egg by egg, the class given by the person with the class given by the equipment, and counts the disagreements by type of defect: dirt, visible crack and shape. A disagreement can come from either side, so the record should show the reason when there is one.

The record should keep the date, the shift, the batch, who did the grading and the class of each egg in both columns, so that someone else can redo the count. To build the reference with eggs already known, see calibrating with labelled eggs.

Which steps should each check follow?

Follow this order in every check:

Choose the sample eggs at different times and points along the line.
Separate the eggs without looking at the class the equipment gave.
Write down the class given by each person and the class given by the equipment.
Compare the two columns and count the disagreements by type of defect.
Record the result on the self-control programme form and decide whether the equipment continues or is adjusted.

If you decide to adjust the equipment, record what changed. The next check then shows whether the adjustment solved the disagreement, and an auditor sees the full history.

What does a sampling check not cover on a camera?

A surface camera sees the shell in reflected light. It doesn't see the air cell, the yolk, internal blood spots or hairline cracks. A camera check therefore covers dirt and visible cracks, and the inside still depends on candling.

A sampling check also does not turn a camera into electronic candling. It shows whether the equipment decides the way a person would on the eggs tested, and nothing beyond that. Vigiovo's per-egg record helps, because each decision comes with its class and the measurements used, which makes the comparison with the person's grading easier. How Vigiovo grades eggs without AI explains each measurement. For the bigger picture on checking every egg against sampling, see inspecting every egg vs sampling.

Frequently asked questions

Does a camera need a manual sampling check?: The MAPA rule on sampling checks is question 34, and it covers electronic candling equipment. A surface camera is not electronic candling, so that rule does not apply to it. Using the same check design is good practice for verifying the camera's results and for showing an auditor how they were validated.
How often should the check run?: This guide gives no number. Frequency is the company's decision, must be justified in the self-control programme, and should be reviewed when the line or the equipment changes. It must be written down before the checks begin, so the record proves the procedure was followed.
Does a manual check prove that the camera sees inside the egg?: No. A sampling check only confirms what the equipment can see. A surface camera does not see the air cell, the yolk or hairline cracks, so sampling cannot validate those items. For the inside of the egg, the reference method remains candling.

Sources

Perguntas e respostas sobre a Portaria MAPA nº 612/2022 (versão de 05/06/2023), Ministério da Agricultura e Pecuária (MAPA)

How Vigiovo helps

Vigiovo grades eggs on the conveyor as clean, dirty, cracked or unverified, in real time, with deterministic computer vision: every decision comes with the measurements behind it, on an ordinary CPU.

See how it works