A NEW METHOD TO MEASURE THE DIFFUSIBLE HYDROGEN CONTENT IN STEEL WELDMENTS USING A POLYMER ELECTROLYTE-BASED HYDROGEN SENSOR

A new technique to measure the diffusible hydrogen content in steel we ldments is described. The sensor, developed at the Indira Gandhi Cente r for Atomic Research, is a conducting polymer film coated with Pd on either side. One side of the sensor was exposed to an argon-hydrogen g as mixture and the other side to air. The current flowing through the sensor was directly proportional to the hydrogen content in the gas mi xture. Hydrogen measurements were also carried out by gas chromatograp hy and one to one correspondence between the results from the gas chro matography and the new sensor was obtained. In addition to these resul ts, advantages of the new sensor over presently available methods for measurement of diffusible hydrogen and its limitations are also discus sed in this paper.