Colour Difference Meter for Quality Control Malaysia

Introduction to Colour Difference Measurement in Manufacturing

Colour consistency is an important quality requirement for manufacturers producing plastic components, painted products, packaging materials, consumer goods and industrial parts. Even small differences between production batches can affect product appearance, customer acceptance and brand consistency.

A Colour Difference Meter helps manufacturers evaluate colour variation using numerical measurement results instead of relying entirely on subjective visual inspection.

For Malaysian factories, a portable instrument such as the Linshang LS172 Colorimeter can support reference-based colour comparison, incoming material inspection, production monitoring and documented quality control decisions.

This guide explains how colour difference meters work, how to establish an effective colour inspection procedure and how the Linshang LS172 can support routine factory quality control.

What Is a Colour Difference Meter?

A Colour Difference Meter is an instrument used to measure colour and calculate the difference between a test sample and an approved reference.

It provides numerical colour information that can help quality control personnel identify variation in finished products or incoming materials.

Depending on the instrument model, measurements may include CIE Lab colour coordinates, Delta E colour difference values and Pass/Fail evaluations.

Main Functions in Factory Quality Control

• Measure the colour of suitable product surfaces.

• Compare test samples against approved master references.

• Calculate numerical colour differences using supported Delta E formulas.

• Evaluate samples against established acceptance tolerances.

• Support batch-to-batch colour consistency checks.

• Provide measurement information for inspection documentation.

A colour difference meter supports quality decisions, but its results should be interpreted according to the material, measurement conditions and relevant customer specifications.

Why Colour Quality Control Is Important

Manufacturers frequently work with raw materials, pigments, coatings and production processes that can introduce colour variation.

Without a consistent inspection method, differences may only become apparent after components have been assembled, packed or delivered.

Common Causes of Colour Variation

• Changes in pigment or colourant concentration.

• Different raw material suppliers or production batches.

• Variations in processing temperature and manufacturing conditions.

• Differences in coating application or curing procedures.

• Changes in surface texture, gloss or finishing.

• Inconsistent visual inspection lighting conditions.

Numerical colour measurement can help factories detect unexpected changes earlier, although identifying the underlying cause may require additional process investigation.

Understanding CIE Lab Colour Values

CIE Lab is a commonly used colour space for describing measured colour using three numerical coordinates.

L* - Lightness

The L* coordinate represents lightness. Lower values indicate darker colours, while higher values indicate lighter colours.

a* - Green to Red

The a* coordinate represents the green-to-red axis. Positive values indicate the red direction, while negative values indicate the green direction.

b* - Blue to Yellow

The b* coordinate represents the blue-to-yellow axis. Positive values indicate the yellow direction, while negative values indicate the blue direction.

By recording these coordinates, quality control personnel can identify not only whether a colour has changed but also the general direction of the measured difference.

What Is Delta E in Colour Quality Control?

Delta E, written as ΔE, is a numerical expression of the difference between two measured colours according to a selected colour difference formula.

A smaller Delta E generally indicates a smaller calculated colour difference, while a larger value indicates greater numerical separation under the selected formula.

However, the relationship between Delta E and visible colour differences depends on the formula, material, surface appearance and viewing conditions.

Common Delta E Formulas

• CIE76 or ΔE*ab, based on distance between CIE Lab coordinates.

• CIE94, which introduces adjustments intended to improve agreement with perceived colour differences in certain applications.

• CIEDE2000, which incorporates additional corrections to account for perceptual nonuniformity.

The appropriate formula should be selected according to customer requirements, the instrument's supported functions and the factory's inspection procedure.

Results from different Delta E formulas should not be treated as numerically interchangeable.

How to Establish Colour Difference Tolerances

A colour difference tolerance defines the acceptable measured variation between a production sample and its approved reference.

The correct tolerance depends on the product, material, customer specification, measurement geometry and selected Delta E formula.

Illustrative QC Example

Suppose a factory has established an internal acceptance criterion of ΔE*ab ≤ 1.0 for a particular product. A measured result of 0.7 would meet that example criterion, while a result of 1.4 would exceed it.

These values are examples only and are not universal industry acceptance limits. Each manufacturer must establish and validate tolerances appropriate to its products and customers.

Factors to Consider When Setting Tolerances

• Customer-approved colour standards.

• Material and surface characteristics.

• Selected Delta E calculation method.

• Instrument measurement geometry and aperture.

• Measurement repeatability and sample variation.

• Controlled visual inspection requirements.

A documented tolerance procedure helps operators make consistent inspection decisions across shifts and production batches.

Using Pass/Fail Colour Inspection

A Pass/Fail function allows an instrument to compare measured colour difference against a configured tolerance.

The Linshang LS172 includes a Pass/Fail function that can support routine reference-based inspection.

Example Factory Inspection Workflow

• Select an approved reference sample.

• Define the applicable colour difference formula.

• Establish the acceptance tolerance.

• Measure the production sample using consistent conditions.

• Review the measured Delta E and Pass/Fail result.

• Record the result and investigate nonconforming samples.

Pass/Fail colour evaluation should be used together with other relevant product specifications, especially where surface defects, gloss or texture are important.

Incoming Material Colour Inspection

Incoming material inspection is an important opportunity to identify colour variation before production begins.

Manufacturers may receive plastic pellets, coated materials, printed packaging or prefinished components from different suppliers.

A colour difference meter can help compare suitable incoming samples against approved reference materials.

Benefits of Incoming Colour Inspection

• Identify unexpected colour variation before production.

• Support supplier quality discussions using numerical results.

• Reduce reliance on visual inspection alone.

• Maintain records for recurring supplier issues.

• Help prevent unsuitable material batches from entering production.

The sampling procedure should account for variation within each incoming batch. A single reading may not adequately represent a large or nonuniform shipment.

Production Batch Colour Consistency Monitoring

Colour variation can occur during manufacturing even when the same nominal raw materials and product specifications are used.

Quality control teams can use a colour difference meter to compare samples collected at defined intervals during production.

Suggested Batch Monitoring Procedure

• Establish an approved master reference.

• Define representative measurement locations.

• Check the instrument according to the manufacturer's instructions.

• Measure samples at documented production intervals.

• Compare results using the same Delta E formula and tolerance.

• Record trends and investigate unusual changes.

Monitoring trends over time can help manufacturers identify gradual colour drift before it leads to widespread product rejection.

Linshang LS172 for Factory Colour Quality Control

The Linshang LS172 is a portable colour measurement instrument designed for reference-based colour comparison and routine industrial inspection.

It uses 45°/0° optical geometry and an 8 mm measurement aperture, making sample suitability and consistent positioning important considerations.

Key Features of Linshang LS172

• 45°/0° optical measurement geometry.

• 8 mm measurement aperture.

• 3.5-inch touchscreen display.

• Approximately 1-second measurement time.

• CIE Lab and other supported colour measurement functions.

• Delta E colour difference evaluation.

• Pass/Fail inspection function.

• Electronic colour chart matching.

• Supported mobile application and Windows PC software.

These features make the LS172 a practical candidate for manufacturers that require portable colour inspection and numerical comparison against approved references.

Industrial Applications in Malaysia

1. Plastic Injection Moulding

Plastic manufacturers can compare suitable molded components against approved master samples. This helps monitor shade variation caused by pigments, resin batches or processing conditions.

2. Paint and Coating Quality Control

Paint and coating manufacturers can evaluate colour consistency on suitable finished panels. Controlled sample preparation and consistent measurement procedures are essential.

3. Printing and Packaging

Packaging manufacturers can use colour difference measurement for suitable printed and coated materials. Applications requiring detailed spectral analysis or printing process control may need specialized instruments.

4. Automotive Component Inspection

Automotive suppliers can evaluate colour consistency on suitable plastic or coated components. Metallic and special-effect finishes may require different measurement equipment.

5. Consumer Electronics and Appliance Manufacturing

Manufacturers of electronic housings, switches, appliance panels and other consumer products can use colour measurement to support consistent product appearance.

How to Perform Colour Difference Measurement Using LS172

Step 1 - Prepare the Approved Master Sample

Choose a stable, clean and representative reference sample that has been approved for the product being inspected.

Step 2 - Check the Measurement Surface

Ensure the test sample provides sufficient uniform area for the instrument aperture. Avoid contamination, uneven contact and unsuitable curved surfaces.

Step 3 - Prepare the Instrument

Follow the manufacturer's operating instructions, including any required calibration or reference verification.

Step 4 - Measure the Reference

Measure and record the approved reference using the selected measurement procedure.

Step 5 - Measure the Test Sample

Position the instrument consistently and obtain the measurement. Additional readings may be necessary for nonuniform materials.

Step 6 - Evaluate Delta E

Compare the calculated colour difference against the documented tolerance using the correct formula.

Step 7 - Record the QC Decision

Document the sample identity, measurement method, reference, formula, result and inspection decision.

Common Mistakes in Factory Colour Inspection

Using Different Reference Samples

Inconsistent master samples can lead to misleading comparisons. Factories should maintain approved references and replace them according to a documented procedure when necessary.

Ignoring Measurement Geometry

Different optical geometries may produce different results. Reference and production measurements should use compatible methods.

Measuring Dirty or Uneven Surfaces

Dust, fingerprints, scratches and surface irregularities may affect measurement results. Appropriate sample preparation is essential.

Using the Wrong Delta E Formula

Different colour difference formulas can produce different numerical values. Operators must use the formula specified by the inspection procedure.

Assuming One Tolerance Fits Every Product

Acceptable colour variation differs between products and customers. Tolerances should be validated for the intended application.

Ignoring Measurement Variation

A single reading may not represent a nonuniform sample. Repeated measurements and defined sampling locations can improve inspection reliability.

Colour Difference Meter vs Visual Colour Inspection

Visual inspection is useful for evaluating overall appearance, but results may vary depending on lighting, observer perception and viewing conditions.

A colour difference meter provides numerical information that can improve consistency in reference-based colour comparisons.

However, instrumental measurement does not eliminate the need for visual assessment. Gloss, texture, metamerism and special-effect finishes may require additional evaluation.

A well-designed quality control procedure may combine instrument measurement with controlled visual inspection.

How to Choose a Colour Difference Meter in Malaysia

Before purchasing a colour difference meter, manufacturers should consider the intended material, measurement method and customer inspection requirements.

Important Selection Criteria

• Suitable measurement geometry for the product surface.

• Measurement aperture compatible with sample dimensions.

• Required CIE Lab and Delta E functions.

• Instrument repeatability and measurement performance.

• Pass/Fail inspection capability.

• Reference storage and data handling requirements.

• Compatibility with customer measurement standards.

• Supplier support and product documentation.

For routine portable colour inspection, the Linshang LS172 may be a suitable option. For detailed spectral analysis, special-effect coatings or specialized standards, a spectrophotometer or another instrument type may be required.

Colour Difference Meter Supplier in Malaysia

MTM Precision Sdn Bhd supplies industrial testing and measuring instruments for manufacturing, engineering and quality control applications throughout Malaysia.

Customers interested in the Linshang LS172 Colour Difference Meter can contact MTM Precision for product enquiries, quotations, application discussions and ordering information.

We serve customers in Kuala Lumpur, Selangor, Johor, Penang, Melaka, Negeri Sembilan, Perak, Pahang, Kedah, Kelantan, Terengganu, Perlis, Sabah and Sarawak.

Frequently Asked Questions

What is a colour difference meter used for?

A colour difference meter is used to compare the measured colour of a sample with an approved reference. It supports production quality control, incoming inspection and batch consistency monitoring.

What does Delta E mean in colour inspection?

Delta E is a numerical expression of colour difference under a selected formula. It helps quality control teams compare samples and evaluate established acceptance criteria.

Can Linshang LS172 perform Pass/Fail inspection?

Yes. The LS172 supports Pass/Fail colour evaluation based on configured colour difference limits.

What Delta E tolerance should a factory use?

There is no universal tolerance for every product. The correct limit depends on the customer specification, material, selected formula and measurement conditions.

Can a colour difference meter replace visual inspection?

Not completely. Instrument measurement provides numerical colour information, while controlled visual inspection may still be required for gloss, texture, special effects and overall appearance.

Where can I buy a colour difference meter in Malaysia?

Contact MTM Precision Sdn Bhd in Puchong, Selangor, for colour difference meter enquiries, Linshang LS172 product information and quotations.

Contact MTM Precision Malaysia

Looking for a colour difference meter for plastic manufacturing, coating inspection, packaging production or factory quality control? Contact MTM Precision to discuss your inspection requirements.

MTM Precision Sdn Bhd

Showroom & Service Centre: No 29-1 & 2, Jalan Bandar 18, Pusat Bandar Puchong, 47160 Puchong, Selangor, Malaysia.

Tel: 03-8080 7172

WhatsApp: +6016-660 7346

Email: mtmpre@yahoo.com

Website: www.mtmpre.com.my

Send us your product or sample photos via WhatsApp, together with your material type and colour inspection requirements, so we can help recommend a suitable measurement instrument.