1. The Testing Standard, IEC 62798:2014: “Industrial electro-heating equipment – Test methods for infrared emitters” describes how emitters are characterized. It defines the test- and constraint conditions. For example, if calculations are to be carried out according to Planck’s radiation law.
2. In line with IEC 62798:2014, Heraeus Noblelight compiles customer information for the operating life of its infrared emitters. Consequently, performance limits are provided depending on
- Tube format (Round tube of diameters from 10mm to 19mm, Twin tubes from 18x8 to 34x14mm)
- Type of reflector (plain, gold, QRC nanoreflector) and
- Emitter type (short wave, fast response medium wave, carbon, medium wave)
3. The performance limits of the infrared emitters are based, on one hand, on a number of internal tests carried out according to IEC 62798:2014 and on the other hand on many years of experience of the emitters in a wide range of applications in industry. Using the evaluation of these combined values, the performance limits for short wave and fast response medium wave can be effectively raised for seven different tube- and reflector-formats.
- For a 23x11mm twin tube with a gold reflector the performance limit is raised from 2x30 W/cm to 2x40 W/cm.
- This means that this emitter can achieve an operating life of more than 10,000 hours if it does not exceed the power density of 80 Watts per cm heated length and it complies with the operating requirements for this emitter.
4. The operating requirements are set down in “Customer information on the operating life of Heraeus Noblelight infrared emitters” (latest: Revision 3/May 2019) There, as well as the operating life limits, you will also find the thermal, mechanical, electrical, chemical and other requirements to achieve optimum operating life. For example, the nominal operating voltage of an IR emitter may never be raised from 100% to 110% for extended periods.
5. Heraeus Noblelight uses an emitter evaluation program, which employs high accuracy algorithms to calculate individual solutions for customers. Detailed data sheets are available with information on electrical and thermal parameters, the peak wavelengths for optimum absorption of customers’ material to be heated and the relevant emitter drawings.
This program is based on both long experience in simulation as well as experimental verification in our Applications Centre, in manufacture and in practical industrial applications.