GE DMS Go+ Operating Manual page 27

Important information on wall thickness measurement using the DMS Go+
Zeroing during probe coupling (ON-BLOCK zeroing)
After coupling the probe (but before each individual wall
thickness measurement), the length of the delay line be-
low the transmitter element is determined at first. The
actual wall thickness measurement is not carried out till
after that.
This method is of advantage whenever a high stability
and reproducibility of the measured values are required.
For example, if the temperature of the part to be tested
differs largely from that of the probe, the delay lines are
cooled down during coupling and thus reduced, or they
are heated up and thus extended. Each zero drift is thus
compensated for immediately before every wall thick-
ness measurement in the case of these probes:
● DA 301 ● DA 303
● DA 312 ● DA 312 B...
● DA 317 ● DA 319
● DA 453* ● DA 461*
● DA 465* ● DA 467*
DMS Go+
In the case of probes marked with *, the zero is deter-
mined as an arithmetic mean of the two probe delay
lines. For example, probes showing beveled wear can
thus comply with their original measured-value toler-
ance better.
● DA 305
● DA 315
● DA 451*
● DA 462*
● DA 469*
Edition 4 (05/2014)
1 Introduction
1-11