GB/T 43603.3-2024 "Methods for Chemical Analysis of Nickel-Platinum Target Alloys, Part 3: Determination of Carbon Content, High Frequency Infrared Detection Method" specifies the method for the determination of carbon content in nickel-platinum target alloys. This standard is applicable for the determination of carbon content in the range of 0.001% to 0.10% mass fraction. During the determination, the sample is heated to combustion in the presence of flux to produce CO2. It enters an infrared detection cell to determine its absorption peak. The mass fraction of carbon is automatically calculated by computer. This document refers to the provisions of GB/T 8170 on numerical revision and GB/T 17684 on the terminology of precious metals and their alloys.