What are the differences between halogen and infrared moisture analyzers?
Thermogravimetric moisture analyzer effectively dries samples by transferring energy through radiation (energy in the form of waves or particles passing through the medium (in this case, the sample)) and convection (heat transfer through mass motion). In contrast, traditional drying ovens mainly use convection to dry samples. Both metal and halogen heating elements radiate energy in the infrared spectrum. Two methods are used in the OHAUS MB series. )
Infrared (IR) radiation is a part of the electromagnetic spectrum that falls between microwave energy and visible light. Infrared radiation includes thermal radiation, with a wavelength frequency range of 0.75 micrometers (the long wavelength limit of visible red light) to 1.5 micrometers (the boundary on microwaves). The human eye cannot see infrared energy. The red light typically associated with infrared heating is actually reflected red light from the visible spectrum.
Some moisture analyzers use metal heating elements, which are simply low resistance metal sheets that convert electricity into heat. This heater is very suitable for environments where the use of glass components is prohibited due to regulatory or safety considerations (such as food processing). Metal heaters are not satisfactory because they generate a lot of heat and require much longer heating time than halogen heaters, making them difficult to control and unable to provide good reproducibility in moisture analyzers.
The halogen radiator is equipped with a tungsten heating element in a compact glass tube, which contains halogen gas to preserve the tungsten element. Halogen radiators emit infrared radiation in the short wavelength range of 0.75-1.5 micrometers. The compact characteristics of halogen radiators improve heating/cooling response time, shorten the time for the heating unit to reach full heating power, and ultimately shorten the time required to complete sample drying. It can also be better controlled during the heating process.
