Standards & Best Practices

As a registered member of the Certified Thermographers Network – Africa (CTN-A), you hereby affirm your commitment to uphold and adhere to the Thermographer's Code of Ethics in all practices.

CTN-A Code of Ethics for Thermographers

At the Certified Thermographers Network – Africa (CTN-A), we uphold the highest standards of ethical and professional conduct in Infrared Thermography. This Code of Ethics outlines the principles and values
that guide our members in delivering reliable, respectful, and responsible
services throughout the continent.

1. Professional Integrity

Conduct all thermographic work with honesty, fairness, and transparency.

Avoid conflicts of interest and disclose any potential biases to clients and stakeholders.

2. Competence and Continuous Learning

Only undertake work for which you are qualified by education, training, and experience.

Commit to continuous professional development to stay abreast of advances in thermographic technology and best practices.

3. Confidentiality and Data Protection

Always protect client information and thermographic data.

Only disclose findings with proper authorization or when required by law.

Adhere to all relevant data protection regulations and ethical standards in handling sensitive information.

4. Accuracy and Objectivity

Ensure all reports and interpretations are accurate, evidence-based, and objective.

Avoid exaggerating or minimizing results.

Clearly communicate any limitations or uncertainties in the findings.

5. Safety and Compliance

Follow all applicable safety protocols and regulatory requirements during inspections.

Use properly calibrated equipment and standardized procedures to ensure safe and consistent operations.

6. Respect and Professionalism

Treat clients, colleagues, and the public with courtesy, respect, and professionalism.

Promote diversity and inclusion.

Avoid any form of discrimination or prejudice.

7. Environmental Responsibility

Minimize environmental impact when conducting thermographic inspections.

Support and promote practices that contribute to sustainability and environmental stewardship within the industry.

8. Accountability

Take full responsibility for your professional conduct and decisions.

Report any unethical behaviour or violations of this Code to the appropriate authorities or professional bodies.

A Commitment to Excellence

This Code of Ethics is the foundation of professional practice for all CTN-A members. By adhering to these principles, thermographers demonstrate a shared commitment to trust, integrity, and excellence in the field of infrared thermography across Africa.

To achieve accurate temperature readings using infrared thermography, it is essential to follow best practices across seven critical factors:

1) Focus
A properly focused image ensures precise temperature measurement. Use manual or automatic focus features to sharpen the thermal image, especially when analysing small or detailed components. An out-of-focus image can lead to temperature averaging and misinterpretation.

2) Spot Size and Target Size
Ensure that the target is significantly larger than the camera’s spot measurement area. A good rule is that the target should be at least 3 to 4 times larger than the spot size to avoid blending background temperatures into the reading.

3) Atmospheric Conditions
Factors like humidity, dust, and ambient temperature affect infrared transmission. Input atmospheric data into the thermal imager when required, and avoid glass or plastic, as these will block or distort infrared radiation.

4) Distance to Target
The further you are from a target; the more atmospheric interference and measurement error can occur. Always stay within the recommended distance for the camera’s resolution (spatial resolution or D:S ratio), ensuring sufficient detectors cover the target for clear analysis.

5) Reflected Apparent Temperature
Reflected infrared radiation from nearby surfaces can affect the accuracy of temperature readings. Use the reflector or direct method as outlined in ISO 18434 to determine the reflected temperature and enter this value into the thermal imager's settings for compensation.

6) Emissivity
Emissivity is the efficiency with which a surface emits infrared radiation. Always adjust the emissivity setting on the thermal imager to match the target material. High-emissivity materials like painted surfaces or electrical insulation provide more accurate readings than shiny metals.

For reflective surfaces, apply emissivity enhancing coatings such as electrical tape or paint to improve accuracy.

7) Viewing Angle
Aim to capture thermal images perpendicular (as close to 90° as possible) to the surface. Tilted angles influence reflection and reduce measurement accuracy. If perpendicular access is not possible, correct for angle-related emissivity changes.

By consistently applying these best practices, thermographers can ensure reliable, repeatable, and accurate temperature measurements in machinery condition monitoring and diagnostics.

Accurate emissivity determination is critical in thermography, as it directly influences temperature measurement accuracy. The reference method, as described in ISO 18434, is one of the most reliable techniques for establishing a material's emissivity under actual operating conditions. This method involves comparing the infrared measurement of a surface to a known temperature reference.

Step-by-Step Procedure:

Identify a SAFE and Stable Test Area
Select a portion of the material’s surface that is clean, flat, and representative of the overall target. The surface should be at a stable operating temperature to ensure consistent readings.

Measure Actual Surface Temperature
Attach a high-emissivity reference such as electrical tape (typically with an emissivity of 0.95) or a painted dot to the selected area. Allow it to reach thermal equilibrium with the surface. Then use the thermal imager to measure the temperature of this reference spot.

Adjust Emissivity on Thermal Imager
Without changing the viewing angle, distance, or focus, measure the temperature of the bare material adjacent to the reference spot. Adjust the emissivity setting on the thermal imager until the measured temperature of the bare surface matches the temperature of the high-emissivity reference. The adjusted value is the estimated emissivity of the material.

Verify and Record
Repeat the procedure at multiple locations (if practical) to confirm consistency. Document the emissivity value, environmental conditions, and surface characteristics for traceability and future reference.

Key Considerations:

Safety First: Ensure the work area is safe before beginning any measurements. Do not approach or touch equipment if there is a risk of electrical shock or exposure to excessive heat that could cause injury. All potential safety hazards must be identified and addressed to maintain a safe working environment.

Surface Preparation: Ensure the material surface is clean and free of oxidation, oil, or coatings that could alter emissivity.

Environmental Control: Conduct the test in stable ambient conditions to avoid interference from wind, moisture, or fluctuating background temperatures.

Viewing Angle: Always perform the comparison from a perpendicular or near-perpendicular angle to minimize reflection and distortion.

Avoid External Heat Sources: Ensure no other hot objects are reflecting onto the target area during measurement.

Advantages of the Reference Method:

Provides a practical and relatively simple way to determine emissivity without needing detailed surface composition data.

Ensures that temperature readings during subsequent inspections are based on realistic emissivity settings for that specific material and surface condition.

By applying the reference method carefully, thermographers can greatly improve the accuracy of thermal measurements, which is essential for effective condition monitoring, diagnostics, and predictive maintenance.

Determining the emissivity of a material is essential for accurate temperature measurement in thermography. The contact method, as outlined in ISO 18434, involves using a direct-contact temperature sensor to compare with infrared readings, allowing for a more precise emissivity setting. This method is particularly useful when non-contact methods are impractical or when high measurement accuracy is required.

Step-by-Step Procedure:

Before starting, confirm that the area is safe. De-energize equipment if possible, especially when working near live electrical components or high temperature surfaces. Wear appropriate personal protective equipment (PPE), such as insulated gloves, arc-rated clothing, and safety glasses. Never place hands or instruments on live conductors or hot surfaces without proper precautions.

Select and Prepare the Measurement Surface
Choose a clean, flat area of the material that is representative of the surface to be monitored. Remove any oxidation, dirt, or paint to expose the true surface material. Consistency in surface condition is vital for reliable results.

Attach a Contact Temperature Sensor
Use a reliable surface-contact temperature sensor (such as a thermocouple or RTD) and firmly attach it to the target area using thermal paste or high-temperature adhesive tape. Allow time for the sensor to reach thermal equilibrium with the surface. Record the temperature displayed by the sensor.

Capture the Thermal Image
With your infrared camera, focus on the same surface area where the contact sensor is attached. Ensure optimal focus, viewing angle (preferably perpendicular), and correct distance. Set the emissivity value on the imager to an initial estimate (e.g., 0.90) and observe the infrared temperature reading.

Adjust Emissivity for Accuracy
Gradually adjust the emissivity setting on the thermal imager until the displayed temperature matches the reading from the contact sensor. The emissivity value at this point is the best estimate for that material and surface condition.

Document the Results
Record the determined emissivity, the type of contact sensor used, surface condition, and environmental conditions. This information is essential for repeatability and future inspections.

Safety Hazards and Mitigation:

• Never place contact sensors on energized electrical equipment unless it is designed for live testing and you are trained and equipped for such tasks.
• Avoid contact with hot surfaces; confirm temperatures with a non-contact method first, and use high-temperature gloves when necessary.
• Watch for moving parts, pinch points, or unstable surfaces.

Conclusion:

The contact method offers high accuracy in determining emissivity, especially when surface conditions and safety allow for direct access. Following ISO 18434 and observing all safety protocols ensures reliable results and protects personnel from harm.

In thermography, accurately determining the reflected apparent temperature is essential for precise surface temperature measurements, especially for low-emissivity materials. According to ISO 18434, the reflector method is a standard and practical approach to estimating this value by simulating the infrared radiation reflected onto the target surface from surrounding objects.

Step-by-Step Procedure:

Before starting, assess all safety risks. When working near energized electrical systems or hot machinery, use appropriate PPE such as arc-rated clothing, insulated gloves, and eye protection. If possible, de-energize equipment to eliminate the risk of electric shock or burns. Be aware of hot surfaces, moving machinery, or unstable platforms.

Prepare the Reflective Material:
Obtain a piece of crumpled and flattened aluminum foil or similar highly reflective, low-emissivity material. This will act as a mirror for ambient infrared radiation. The foil should be clean and wrinkle-free enough to reflect surrounding objects clearly, but dull enough to avoid acting as a direct mirror.

Place the Reflector Near the Target Surface
Secure the foil close to the surface whose temperature you wish to measure. Ideally at the same angle and orientation. It must reflect the same environmental conditions affecting the target. Avoid letting the foil touch live components or hot surfaces. If placement near energized equipment is required, maintain safe distances or use non-conductive holders.

Set the Thermal Imager’s Emissivity to 1.0
On your infrared camera, set the emissivity to 1.0 (assuming a perfect blackbody) and distance to 0 meters to minimize atmospheric influence. This setting allows you to isolate the reflected radiation being captured by the foil.

Measure the Apparent Temperature of the Reflector
Focus the thermal imager on the foil and measure its apparent temperature. This value represents the reflected apparent temperature from the environment, which should be used in all subsequent measurements involving that surface or area.

Input the Reflected Temperature into the Thermal Imager
Update the reflected apparent temperature setting in your imager with the measured value. This will improve the accuracy of surface temperature calculations, especially for materials with low emissivity.

Key Safety Hazards and Precautions:

• Electrical Shock: Never place foil near live electrical components unless equipment is isolated or you're trained and wearing certified PPE.
• Burn Injuries: Avoid placing the reflector on or near high-temperature surfaces that could ignite materials or cause skin burns.
• Reflected Heat: Be cautious of hot equipment radiating heat back onto your face or hands while positioning the reflector.

Conclusion:

Using the reflector method per ISO 18434 is a reliable way to determine reflected apparent temperature. When done safely and accurately, it significantly enhances thermographic measurement precision in real-world industrial environments.