Among the characteristics of climate or thermal test chambers, there is a variable that indicates the maximum speed that the chamber can reach for both heating and cooling. In order to define this gradient, the test standards to be applied normally indicate the recommended or maximum gradients for performing the tests.
We must not make the mistake of thinking that a higher gradient is better for reducing test times, as these increases can generate greater thermal stresses in the samples and can cause thermal stress within the sample. Many standards establish a maximum gradient to avoid this effect on the samples. Read the test standards carefully in order to select the most appropriate temperature gradient.
Please note that the gradients provided by chamber manufacturers are based on the IEC 60068-3-5 standard, the average temperature rate within the chamber without load and measured between 10% of the positive and negative temperatures of the chamber’s total temperature range. That is, for a climatic chamber from -40°C to +180°C, the temperature gradient according to IEC 60068-3-5 will be between -22°C and +158°C. This information is used to standardise gradient values, but this value is not always useful for selecting the most suitable chamber. The gradient will be reduced depending on the mass to be tested, the type of material, the sample’s heat dissipation capacity, etc. You must provide as much information as possible to ensure that the climatic chamber will meet your needs and those of the sample you wish to test.
Always consult DYCOMETAL’s technical sales department to select the equipment that best suits your needs.
