13
en
1.
Remove all couplant from the face of the transducer and
check that the wearface of the transducer is clean and
free of any debris.
2.
Use the control button to select
ZERO
from the top level
menu items.
The zero submenu items begin scrolling.
3.
Apply a drop of couplant on the transducer and place the
transducer in steady contact with the zero disk (located
on the bottom end cap), and obtain a steady reading.
Note: Do not remove the transducer from the zero disk.
The measurement display should show a thickness
value, and nearly all the bars of the stability indicator
should be illuminated.
Note: The value that is displayed will change depending
on the current velocity setting in your gauge. Disregard
the value displayed; it is not important. What is important
is accurately performing these steps to ensure reliability of the zero calculation.
4.
Use the control button to select
COAT
from the submenu items.
The gauge performs the coating zero.
5.
Remove the transducer from the zero disk.
7.4 CALIBRATING
In order for the gauge to make accurate measurements, it must be calibrated to the sound-velocity
of the material being measured.
Different types of material have different sound-velocities. For example, the velocity of sound
through steel is 5918 m/s (about 0.233 in/µs) and the velocity of sound through aluminium is
6350 m/s (about 0.248 in/µs). If the gauge is not set to the correct sound-velocity, all of the
measurements the gauge makes will be erroneous by some fixed percentage.
To calibrate your gauge for the material you are measuring, you select the material from a list of
materials stored in the gauge. For each material stored in the list there is a corresponding
sound-velocity value. There are eight factory-set materials which you cannot change, plus one user
customisable sound-velocity value:
Submenu
Item
Material
Sound-velocity
m/s
in/µs
ALU
Aluminium
6350
0.2500
STL
Steel 4340
5918
0.2330
STST
Stainless Steel 304
5662
0.2229
IRON
Iron
5893
0.2320
CIRO
Cast Iron
4572
0.1800
PVC
PVC
2388
0.0940
PLST
Polystyrene
2337
0.0920
PLUR
Polyurethane
1778
0.0700
CUSTOM
User-defined sound-velocity
-
-
0$18$/
Zero Disk
