Thermal Conductivity Tester – Heat Flow Meter

Parent Product

Heat Flow Meter - Thermal Conductivity Tester

Product Categories

Plastic Testing Equipment

Concrete Testing Equipment

View PDF

Thermal Conductivity Tester (TPS Method) – High-Precision Heat Flow Meter QualiHFM™-1000

The Thermal Conductivity Tester utilizes the advanced Transient Plane Source (TPS) method to deliver fast, highly accurate measurements of thermal properties. Designed for versatility, this instrument is the ideal solution for R&D labs and Quality Control centers testing a wide variety of materials—from bulk solids to liquids and pastes.

Fully compliant with ISO 22007-2:2008, this device eliminates the common errors associated with static testing methods, offering a robust solution for measuring thermal conductivity, thermal diffusivity, and specific heat capacity.

Versatile Material Compatibility

This unit is engineered to handle a broad spectrum of material states and types, including:

Solids: Bulk insulation, polymers, metals, and ceramics.
Fluids: Liquids, pastes, and colloids.
Complex Structures: Granular materials, powders, coatings, and thin films.

Efficiency & Speed

Rapid Testing: Adjustable test durations between 5 to 160 seconds allow for high-throughput testing without sacrificing accuracy.
Direct Measurement: Measures thermal properties directly, removing the need for complex calibration curves.

Unmatched Accuracy

ISO Compliance: Strictly follows ISO 22007-2:2008 standards for international quality assurance.
Advanced Data Processing: Powered by an ARM microprocessor and high-resolution data chips, the system delivers faster analysis and higher precision than conventional thermal analyzers.
No Contact Resistance Errors: The transient method effectively negates errors caused by contact thermal resistance, a common failing of static heat flow meters.

User-Friendly Design

Minimal Sample Prep: No complex machining is required. Bulk solids only need a relatively smooth surface (at least twice the probe diameter).
Smart Interface: Features a large, color LCD touchscreen for intuitive control and real-time data visualization.
Automated Reporting: Includes robust software for automated PC communication, data management, and instant report generation.

Transient Plane Source (TPS) Method: Mechanics & Measurement Principles

flowchart LR
    A[QualiHFM-1000 double-helix probe sandwiched between sample halves] --> B[Adjustable 5-to-160-second controlled electrical heat pulse]
    B --> C[Real-Time Resistance Logging via ARM Microprocessor & High-Res Chips]
    C --> D[Convert Resistance Shifts into Temperature Response]
    D --> E[Map Temperature Climbs Against ISO 22007-2:2008 Math Models]
    E --> F[Direct Calculation of Thermal Conductivity, Diffusivity & Heat Capacity]

Step-by-Step Measurement Process

Proprietary Sandwich Setup: A planar double-helix probe sits flush between two matching layers of your sample material, bypassing the long wait times required by static testing methods.
Controlled Joule Heating: An adjustable 5-to-160-second electrical current warms the double-helix probe, sending a controlled transient heat wave into the surrounding material.
High-Resolution Resistance Tracking: As thermal energy dissipates into surrounding sample layers, high-resolution data collection chips log electrical resistance changes across the probe at high frequencies.
ARM Microprocessor Processing: An ARM microprocessor translates electrical resistance shifts into temperature responses using the probe's known thermal reaction rate.
Dimensionless Curve Fitting: The measured temperature curve gets mapped against mathematical time-delay models compliant with ISO 22007-2:2008 standards.
Direct Multi-Property Calculation: The system calculates thermal conductivity, thermal diffusivity, and specific heat capacity directly without requiring complex calibration curves or destructive sample heating.

Sensor Physics & Theoretical Assumptions

The QualiHFM™-1000 relies on dynamic heat transfer equations where a single thermoresistive element acts simultaneously as the heat source and the temperature sensor:

Double-Helix Probe Assembly: The planar probe features a conductive nickel double-spiral pattern enclosed within thin insulating film layers, providing uniform radial heat distribution into surrounding sample halves.
Governing Math Model: The average temperature rise (ΔT) of the planar sensor relates directly to dimensionless time D(τ):
ΔT(τ) = (I² · R₀ · α_R) / (π^3/2 · r · k) · D(τ)
Where I is electrical current, R₀ is initial probe resistance, α_R is the temperature coefficient of resistance, r is sensor radius, k is thermal conductivity, and D(τ) is the time-dependent theoretical function.
Idealized Boundary Assumptions:
- Semi-Infinite Sample Boundaries: Material layers remain thick enough (at least twice the probe diameter) that heat never reaches outer edges during the test window.
- Zero Sensor Thermal Mass: The planar probe stays thin enough to carry zero noticeable heat capacity of its own.
- Negligible Contact Resistance: Dynamic transient calculations eliminate thermal contact resistance errors that typically degrade static heat flow meters.
- Flat Step-Function Heating: Input wattage arrives as an instantaneous, strictly controlled step function.

Technical Specifications (QualiHFM™-1000 TPS System)

Testing Parameter	QualiHFM™-1000 Hardware Specifications
Product Model	Thermal Conductivity Tester (TPS Method): QualiHFM™-1000
Core Measurement Method	Transient Plane Source (TPS) Method
International Standard	ISO 22007-2:2008 (Plastics: Transient plane heat source method)
Processing Hardware	ARM Microprocessor with High-Resolution Data Processing Chips
User Interface	Large Color LCD Touchscreen Display with Automated PC Reporting Software
Measured Properties	Thermal Conductivity, Thermal Diffusivity, and Specific Heat Capacity
Test Duration	Adjustable between 5 seconds and 160 seconds
Sample Preparation	Minimal prep (requires relatively smooth surface at least twice probe diameter)
Direct Calculation	Direct measurement output without needing complex calibration curves

Practical Error Corrections & Systemic Advantages

Contact Resistance Negation: Static heat flow meters suffer from contact thermal resistance errors between sample surfaces and test plates. The QualiHFM™-1000 transient math models isolate thermal contact resistance, delivering accurate figures without elaborate sample machining.
Electrical Wattage Tracking: Heating wire resistance shifts as temperatures rise. Real-time voltage monitoring balances energy delivery to prevent systematic calculation errors.
Insulation Mass Subtraction: The thin protective casing around the double-spiral wire absorbs a fraction of initial heat. Time-zero software shifts subtract insulation mass artifacts before calculating final material properties.
Automated Time-Window Selection: Built-in ISO 22007-2:2008 software algorithms evaluate data between 60% and 80% of total heating runs, removing operator bias and reducing measurement variation by nearly 60%.

Versatile Material Compatibility & Testing Capabilities

The QualiHFM™-1000 handles a broad spectrum of material states and structural compositions:

Solids & Bulk Samples: Tests bulk insulation blocks, dense polymers, ceramics, and structural metals with minimal sample preparation, requiring only a relatively flat surface at least twice the probe diameter.
Fluids & Pastes: Measures liquids, pastes, and colloidal suspensions directly without requiring specialized calibration curves.
Powders & Thin Films: Evaluates loose granular materials, fine powders, industrial coatings, and thin films.
Anisotropic Composites: For fiber-reinforced composites or graphite sheets with direction-dependent conductivity, TPS calculates both through-plane and in-plane properties within a single test run when heat capacity is known.

Thermal Conductivity Tester – Heat Flow Meter QualiHFM™-1000 Technical Specifications

Model	QualiHFM™-1000
Measurement Method	Transient Plane Source (TPS)
Thermal Conductivity Range	0.0001 - 300 W/(m·K)
Measurement Accuracy	±3%
Repeatability Error	≤3%
Measurement Time	5 - 160 seconds (Adjustable)
Sample Temperature Range	-20°C to 320°C (Requires external temperature control equipment)
Sample Temperature Rise	< 15°C during test
Probe Diameters	Probe 1: 7.5 mm Probe 2: 15 mm Probe 3: 30 mm
Required Sample Dimensions (Single Sample Size)	For Probe 1: ≥ 15 × 15 × 3.75 mm For Probe 2: ≥ 30 × 30 × 7.5 mm For Probe 3: ≥ 60 × 60 × 20 mm
Probe Power Output	Probe 1: 0 < P < 1 W Probe 2: 0 < P < 14 W Probe 3: 0 < P < 14 W
Power Supply	AC 220V (110V option available), < 500W Power Consumption
Control System	ARM Microprocessor with High-Resolution Data Chip

Thermal Conductivity Tester – Heat Flow Meter