Elcometer CG20 Operating Instructions Manual page 14

6.2 PROCEDURE
1. Apply couplant
For the gauge to work correctly there must be no air gap between the transducer and the surface of
the material to be measured. This is achieved using a couplant.
Before the transducer is placed on the surface, put a small amount of couplant on the surface of the
material. Typically a single drop is sufficient.
2. Place transducer onto the surface of the material to be measured
Press the transducer wearface into the couplant. Moderate pressure on the top of the transducer using
the thumb or index finger is sufficient; it is only necessary to keep the transducer stationary and the
wearface seated flat against the surface of the material.
3. Read display
If six or seven bars of the stability indicator are showing, the display will be reading the correct thick-
ness of the material directly beneath the transducer.
If the stability indicator has fewer than five bars showing, or the numbers on the display seem erratic,
check to make sure that there is an adequate film of couplant beneath the transducer, and that the
transducer is seated flat against the material.
The gauge will perform a number of measurements every second when the transducer is in contact
with the surface of the material. The display is updated as each reading is taken.
4. Remove transducer from surface
The display will show the last measurement made.
Note: Occasionally, a small film of couplant that is left on the transducer surface will be measured by the
gauge as it is removed. Using less couplant can reduce this effect.
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