~ Summary ~
We conducted a precise thermographic analysis for out client's graphene-based heating product. Applying grey-body methodology, thermal imaging and thermocouple comparisons confirmed a reliable emissivity of 0.95 across the operational range. This provides the foundation for accurate diagnostics and performance monitoring. A crucial study for emerging heating technologies.
Introduction
We were approached by an advanced materials manufacturer to carry out a detailed thermographic assessment of a graphene-based underfloor heating panel constructed using graphene conductive ink. The goal of this technical investigation was to determine an accurate surface emissivity value for this innovative heating material, a vital prerequisite for reliable thermal performance monitoring, diagnostics, and quality assurance in real-world installations.
Testing Location & Setup
All testing was carried in a controlled environment at our studio testing facility in Sussex. A 600 mm x 530 mm graphene PET-laminated panel was mounted onto an insulated base and powered using a regulated bench supply (48V @ 1.25A, ~60W). Ambient air was stabilised at 16°C with minimal airflow, and no direct light or solar gain influenced the test area.
We employed a comparative grey-body method using Scotch Super 88 electrical tape (ε = 0.95) as a reference material. Type-K thermocouples were applied beneath both the tape and graphene surface, while a high precision thermal camera was used to capture progressive thermal images as the panel heated in 1°C increments from 16°C to 34°C.
Graphene, Emissivity, Underfloor Heating, Thermal Imaging, Test Lab, Thermocouple, Calibration, Heating Technology
Thermographic Process
A reference temperature patch was established using the tape, with matching measurements taken across a larger graphene surface region to minimise the influence of any localised inconsistencies in surface conductivity or lamination.
At each step, post-processing analysis adjusted the emissivity value of the graphene region until the apparent temperature matched that of the reference tape. By matching thermographic and thermocouple readings, we were able to validate emissivity to a high level of confidence.
Summary Findings
The test results confirmed that the graphene surface exhibited consistent radiative behaviour at an emissivity of 0.95 across its operational range. Minor deviations observed above 28°C (the product’s specified upper limit) showed a subtle downward trend, dropping to ε = 0.90 at 34°C. However, these were not deemed significant for real-world applications.
Key to the successful outcome was the decision to monitor a broad surface area for the test region. This approach ensured minor surface variations were averaged out, producing a reliable emissivity figure suitable for standard thermography camera presets.
Outcome & Recommendations
This investigation successfully validated that an emissivity setting of 0.95 can be confidently applied to the graphene heating surfaces when using thermal imaging for performance checks or maintenance assessments.
For elevated temperatures above 28°C, a reduction in emissivity may be expected, but this falls outside normal operational thresholds and does not compromise diagnostic accuracy for intended use cases.
The test demonstrates how detailed laboratory-based thermography, combined with precision instrumentation and methodical procedures, can provide manufacturers and engineers with robust thermal characterisation for next-generation materials.
