Appendix B. Typical Applications; H2 In N2 In Heat Treat Furnace Atmospheres; Problem; Equipment - GE XMTC User Manual

Appendix B. Typical Applications

B.1 H in N in Heat Treat Furnace Atmospheres
2 2
The XMTC can be used to measure the concentration of hydrogen (H
atmosphere.
B.1.1 Problem
Mixtures of H and N are used as controlled atmospheres in the heat treating of metals. These mixtures are
2 2
well-defined and need to be maintained in order to assure product quality and consistency. Dissociated ammonia is one
such atmosphere. Here, ammonia is broken down into free N
B.1.2 Equipment
A typical instrumentation package includes a 2-port (Sealed Reference Gas - air) XMTC transmitter with a 4-20 mA
range of 0-25% H mounted in a sample system similar to the one shown in Figure 56 below. A display package is
2
often specified.
XMTC User's Manual
ZERO GAS
INLET
N2
SPAN GAS
INLET
N3
SAMPLE
INLET
N1
Figure 56: Sample System
) in nitrogen (N
2
and H in a 25 to 75% mixture.
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SAMPLE
OUTLET
OUTPUT
INPUT
N4
Appendix B. Typical Applications
) in a heat treat furnace
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