Egg Internal Grade Measurement Tool

This device measures the internal quality attributes of shell eggs without breaking the shell. It provides quantitative data on albumen height, yolk diameter, and derived indices such as the Haugh unit, which are key indicators of freshness and functional performance.

Accurate internal grading supports breeding programs, hatchery management, and downstream processing by linking egg composition to shelf‑standing, foaming capacity, and gel strength. The tool enables objective sorting, reduces reliance on subjective candling, and supplies traceable data for quality assurance systems.

Measurement Principle

The instrument uses a collimated LED back‑light source and a high‑resolution CMOS sensor to capture a silhouette of the egg’s interior. By analysing the vertical extent of the albumen layer and the horizontal dimensions of the yolk, the software calculates albumen height and yolk diameter in millimetres.

The Haugh unit is then computed from the albumen height and egg weight using the standard formula. Reference eggs measured concurrently provide traceability to national standards, and the built‑in calibration routine compensates for sensor drift and ambient temperature variations.

Key Technical Specifications

Design and Materials

The enclosure is formed from AISI 304 stainless steel with a brushed finish, providing resistance to cleaning agents and compliance with food‑zone equipment standards. All surfaces that contact the egg shell are polished to Ra ≤ 0.8 µm to minimise microbial adhesion.

The imaging chamber incorporates a food‑grade acrylic window (PMMA) with UV‑stable coating, selected for low distortion and high transmission in the 470‑530 nm band used by the back‑light LEDs. Internal wiring is routed through sealed glands rated IP65, protecting electronics from splashes and dust.

Applications in Poultry Processing

In breeding farms, the tool supports selection of lines with superior albumen quality, which correlates with chick hatchability and early growth. Hatcheries use it to monitor egg storage conditions, adjusting temperature and turning schedules based on observed Haugh unit trends.

Egg processors integrate the device at receiving stations to divert sub‑standard lots before breaking, thereby reducing waste in liquid egg or powder lines. Research laboratories employ the instrument for studies on feed additives, lighting programs, and ageing effects, benefitting from its non‑destructive repeatability.

Customization Options

• Alternative LED wavelengths (e.g., 660 nm for pigment‑sensitive assays)
• Adjustable sample tray to accommodate specialty eggs (quail, duck)
• Software modules for statistical process control, SPC charts, and ERP connectivity
• Extended temperature range (−10 °C to 50 °C) with insulated housing
• Battery‑powered portable version for field audits

Quality Assurance and Calibration

Each unit undergoes factory calibration against a set of reference eggs with certified Haugh unit values, traceable to ISO 17025 standards. Calibration data are stored in non‑volatile memory and can be restored via the service menu.

Field verification is recommended monthly using a supplied calibration plate that simulates known albumen heights. The software flags deviations beyond ±0.15 mm and guides the operator through a corrective adjustment routine.

Frequently Asked Questions