Patent ID: 11971349
Assignee: NCS JIANGSU TESTING TECHNOLOGY CO., LTD.
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 4:
5. A combined oxygen, nitrogen and hydrogen joint determination method based on thermal conductivity-infrared technique, which is applied in the combined oxygen, nitrogen and hydrogen joint determination device based on thermal conductivity-infrared technique of claim 2, comprising the following steps:
a sample of metal or alloy material is put into the impulse furnace to release oxygen, nitrogen and hydrogen as CO, N2 and H2 molecules as analytical gases;
the carrier gas introduction pipeline is controlled to introduce high-purity He or high-purity N2 as a carrier gas;
one branch of the introduced carrier gas enters the TC cell through the reference valve and the needle valve as the reference gas, and the other branch enters the chamber valve, when the sample is analyzed in the working state, the carrier gas is blown into the impulse furnace to carry the analytical gas released from the molten sample into the dust filter;
the analytical gas passing through the dust filter enters the flush valve, and the flush valve is opened at the degassing stage at the beginning of the analysis to exhaust waste gases; and after degassing, the analytical gas containing components to be determined passes through the bypass valve and the mass flowmeter in sequence;
when high-purity He is introduced as the carrier gas, the analytical gas is carried by the carrier gas to enter the IR cell through the first switching valve, the converter and the second switching valve in sequence and then enter the TC cell through the analysis purification reagent tube to realize O/N joint determination, N/H joint determination and O/N/H joint determination, wherein oxygen and hydrogen are determined by the IR absorption method, and nitrogen is determined by the TC method;
when high-purity N2 is introduced as the carrier gas, the analytical gas is carried by the carrier gas to enter the IR cell through the second switching valve and then enter the TC cell through the analysis purification reagent tube to realize the O/H joint determination mode, wherein oxygen is determined by the IR absorption method, and hydrogen is determined by the TC method.