GB/T 4699.4-2008 Ferrochromium and silicochromium -Determination of carbon content - Infrared absorption method and gravimetric method
WARNING: Persons using this part shall be familiar with normal laboratory practice. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user to establish appropriate safety and health practices and to ensure compliance with any national regulatory conditions.
1 Scope
This part specifies the determination of carbon content in ferrochromium and siliconchromium by infrared absorption method and gravimetric method.
The infrared absorption method in this part is applicable to the determination of carbon content in ferrochromium and siliconchromium, ranging from 0.010% ~ 10.50% (mass fraction); the gravimetric method is applicable to the determination of carbon content in ferrochromium, ranging from 4.00% ~ 10.50% (mass fraction).
2 Normative references
The following normative documents contain provisions which, through reference in this part, constitute provisions of this part. For dated references, subsequent amendments (excluding corrections) to, or revisions of, any of these publications do not apply to this part. However, parties to agreements based on this part are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document applies.
GB/T 4010 Ferroallys sampling and preparation of samples for chemical analysis
3 Method I – Infrared absorption method
3.1 Principle
The test portion is heated and combusted in an oxygen flow within a high-frequency induction furnace. The generated carbon dioxide is carried by oxygen to the measuring chamber of an infrared analyzer. Carbon dioxide absorbs infrared energy at a specific wavelength, and the amount of absorbed energy is directly proportional to its concentration. The carbon content is determined based on the change in energy received by the detector.
3.2 Reagents and materials
3.2.1 Acetone: residue after evaporation, having a carbon content of less than 0.0005%.
3.2.2 Magnesium perchlorate: anhydrous, granular.
3.2.3 Caustic soda asbestos: granular.
Foreword i
1 Scope
2 Normative references
3 Method I – Infrared absorption method
4 Method II — Gravimetric method
5 Test report
