Guarded Hot Plate/Guarded Hot Pipe

This is a list of questions, that can be answered with this method. Of course, there are many more.

• How is a particular insulation material performing?
• How can cryo-tanks be insulated the best possible way?
• Does cryogenic insulation reliably prevent heat exchange?
• What is the optimum insulation for furnaces operating under different temperature, gas or pressure conditions?
• Is the thermal conductivity low enough to prevent thermal bridges?

Whenever traceability and adherence to ISO 8302 or EN 12667 are required for an insulating material’s thermal conductivity, the NETZSCH GHP is the go-to choice.

NETZSCH's Guarded Hot Plate (GHP) instruments provide highly accurate and precise measurements of the thermal conductivity, thermal resistance, and resulting U-values for low-conductivity materials. In accordance with ISO 8302 and ASTM C177, the GHP 500/600/900/900S devices are ideal for research, development, and quality control in the insulation industry and beyond as the reference method. 

However, the GHP models differ in sample size, test chamber accessibility, and intended use. The GHP 500/600/900 models are ideal for medium to large samples; GHP 900 S adds tilting functionality; and the GHP 456 Titan^® is a compact option for small samples with the possibility to choose between a low‐temperature version (‐160°C to 250°C) and the high‐temperature version (‐160°C to 600°C).

Please find here the detailled differentation:

GHP 500

• Sample size up to 500 x 500 mm
• Heating area: 200–300 mm
• Sample thickness: up to 200 mm
• Plate temperature range: -15°C to +70°C
• Ideal for standard insulation materials in labs and QC

GHP 600

• Sample size up to 600 x 600 mm
• Same heating area and temperature range as GHP 500
• Increased capacity for larger insulation panels

GHP 900

• Sample size up to 900 x 900 mm
• Heating area: 200–500 mm
• Sample thickness: up to 280 mm
• Designed for large and heavy specimens

GHP 900 S

• Same technical specifications as GHP 900
• Additional tiltable test chamber for angled sample measurements (e.g., glazing units)

Please feel free to consult with our NETZSCH experts to choose the best-suited GHP model for your specific needs. 

The great advantage of the GHP method is that it is an absolute method; i.e., no calibration or correction is required at all. The thermal conductivity values result in the stationary state simply from the: 

• precisely measured total power input into the hot plate, Q,
• average sample thickness, d,
• measurement area, A, and
• mean temperature difference, ΔT, along the sample or the two samples, as the case may be (the factor 2 results for two samples):

The GHP method is described in, e.g., ISO 8302, ASTM C177 or DIN EN 12667.

Yes. All GHP 500/600/900 models feature cooling and heating plates, enabling tests from -15°C to +70°C depending on the configuration.

The GHP 456 Titan^® is available for a temperature range from -160 to 250°C (low-temperature version) or -160 to 600°C (high-temperature version).

NETZSCH GHP instruments can measure materials with thermal conductivities as low as 0.005 W/(m·K), making them ideal for high-performance insulators like VIPs and aerogels.

Yes. Our touchscreen and Windows-based Lambda software offer intuitive setup, automated measurement sequences, and comprehensive data analysis.

No, the GHP method is absolute and does not require calibration standards for each measurement.

The key difference between thermal conductivity and thermal resistance lies in what they describe and how they are measured:

Thermal ConductivityThermal conductivity (λ with the unit W/(m•K)) describes the transport of energy – in the form of heat – through a body of mass as the result of a temperature gradient (see fig. 1). According to the second law of thermodynamics, heat always flows in the direction of the lower temperature.Thermal Conductivity:

• Definition: It is a material property that quantifies how well a material conducts heat.
• Unit: Measured in W/m·K (watts per meter per kelvin).
  Key Concept:
  • A high thermal conductivity means heat flows easily through the material (e.g., metals like copper or aluminum).
  • A low thermal conductivity indicates the material is a good thermal insulator (e.g., insulation materials, VIPs (Vacuum Insulation Panels), ceramics, polymers).

Thermal Resistance:

• Definition: It quantifies how effectively a material or system resists the heat flow. It is not a material property but depends on the geometry and thickness of the material.
• Unit: Measured in K/W (kelvin per watt).
• Key Concept:
  • High thermal resistance means the material or system effectively resists the heat flow. (good insulator).
  • Low thermal resistance indicates efficient heat transfer (good conductor).

Visit also our glossary to learn more:

The cost of a NETZSCH Guarded Hot Plate or Guarded Hot Pipe can significantly vary depending on the model, features, and any additional accessories or software options you may require.

To get an accurate and up-to-date price for your individual NETZSCH GHP Instrument, please contact your local NETZSCH representative or one of our authorized distributors. We will provide a quote tailored to your specific requirements, including any necessary training, installation, or additional features.

Our current delivery time is approximately 8-12 weeks, depending on the specific configuration of the GHP and current demand. For more complex customizations or during periods of high demand, the delivery time may extend beyond this range. 

For the most up-to-date information, we encourage you to contact us directly with a specific request. This will ensure that we can provide you with an accurate timeline tailored to your specific needs.

Our NETZSCH applications laboratory is providing contract testing services for a wide range of industries and research centers. It is equipped with state-of-the-art GHP testing instruments allowing for a variety of thermophysical property measurements to be carried out. 

Whether you're benchmarking insulation materials, evaluating composites, or developing thermal interface materials, our professional laboratory offers access to cutting-edge instruments and expert support — without the need for in-house equipment.

Consult the NETZSCH experts in our applications labs to choose the best-suited measuring method for your specific needs. You will be working with our experienced scientists (physicists, chemists, materials scientists), possessing consolidated knowledge of the most varied methods and materials spectra. 

We offer:

• Installation and Commissioning
• Relocation of your instrument
• Maintenance and inspection
• Calibration
• Repair
• Comprehensive training from basic to advanced use of the instrument - on-site and online.

Please note that our service may vary from region to region.

Our Remote Service is available worldwide.

Yes, we offer maintenance contracts for your instruments according to the different regional and individual customer requirements. Please feel free to contact our Service Department or take a closer look at our website section Service-Level Agreement - NETZSCH Analyzing & Testing.

Thanks to the integrated single board computer (SBC) with Windows operating system, the Lambda software and the high-resolution color touch display, the devices are very user-friendly. Data acquisition, processing, and control are thus easily handled. Download our brochure to learn more:

• Guarded Hot Plate Series - GHP 500, GHP 600, GHP 900 and GHP 900 S

  Brochure

  (pdf – 1.32 MB)

We offer online training via our NETZSCH Online Academy NOA, 1:1 remote training and on-site training at your location or our training centers. Simply contact your sales representative or go to Training & Know-how - NETZSCH Analyzing & Testing