How To Measure - DeFelsko PosiTector UTG Guide D'utilisation

The PosiTector UTGM in multiple-echo mode
thickness by measuring the time between at least three
consecutive back wall echoes.
Probe
t
In the figure above, multiple-echo mode measures only the
time between echoes. Regardless of whether the steel is coated
or not, all times between echoes are the same. In multiple-echo
mode the Gage determines thickness by measuring
dividing it by six and then multiplying by the velocity of sound for
that material. The resultant thickness calculation made by the
instrument is therefore an accurate measurement of the steel
thickness only, disregarding the coating thickness.
The velocity of sound is expressed in inches per microsecond or
meters per second. It is different for all materials. For example,
sound travels through steel faster (~0.233 in/µs) than it travels
through plastic (~0.086 in/µs).
1. Remove rubber cap from probe.
Couplant (glycol gel - included) must
be applied to the surface to be tested
to eliminate air gaps between the wear
face and the surface. A single drop of couplant
is sufficient when taking a spot measurement.
2. Place the probe flat on the surface. Use moderate pressure to
press against the top of the probe with the thumb or index finger.
t
1
2 3

How to Measure

Figure 2
3
determines
t
t
1
2 3
t + t + t
1 2
,
3