- 24 -
6. Please note
1) Remove dust, dirt, rust or other contaminants which may adversely affect the measurement result
before measuring.
2.) A too rough surface could disturb a measurement, so that an error is displayed. Grind / polish the
surface at the point being measured to make a measurement. If no measurement is possible, this may be
due to the surface properties, the material or a weak point in the material, which is not visible from the
outside.
3.) For measurements of tubes and pipes you must pay attention to the use of the right measuring
transducer. For pipes with larger diameter use the 10mm sensor and for tubes with a smaller diameter,
use the 6mm sensor. If the pipe is bent very strong, so that the sensor can’t be positioned properly, use
the smaller sensor, since this also has a smaller contact area. For measurement turn the sensor if
necessary by 90° and repeat the measurement. The smaller measurement result is the correct
measurement value at this point.
4.) To get a satisfying ultrasonic response, the surface must have its one measuring side parallel with
another, otherwise will obtain wrong result. Search -if possible- a place of upper and lower sides as
parallel as possible and repeat the measurement.
5.) The speed of sound in materials may change due to the temperature of the workpiece. If necessary,
perform a control measurement on a second workpiece or adjust the speed of sound as described in
Section 5.3.
6) Sound-absorbing materials such as fibrous, coarse-pored or gritty materials can falsify the
measurement result. In this case, the meter is not suitable for the intended application.
7.) For calibrations this meter has a sample block with 4mm thickness. For increased precision (as in
repetitive applications) is however recommended to use a sample block from the respective measured
material, as described in Section 5.3.
8.) The transducer may wear out due to misuse, normal wear or sharp edged surfaces. Are the readings
illogical or there are readings also displayed permanently without coupling to a workpiece, the sensor may
be worn and should not be used anymore.
9.) Use to set the ▼ ▲ keys to zero the measured value to 0.000, when the sensor is not resting on a
workpiece. This increases the measurement accuracy. Run also regular calibrations of the device with the
integrated sample block.
10) In composite material, the ultrasound can’t evenly diffuse. Therefore, the measurement results in
composite material consisting of layers of different materials are inaccurate or completely false, because
the measuring principle used the ultrasound reflection is not applicable here. A heavily oxidized surface
can already act as a second material layer in this case, since the speed of sound in the oxidized material
can spread differently than the non-oxidized core of the workpiece.
11) Use the correct ultrasound coupling gel. The enclosed gel can be applied for all materials. It may be
useful for rough surfaces or aluminum to use a gel with a higher viscosity such as to use glycerine as
commercially available items, for increased precision.
6.1 Selection of Transducer
Recommended Operating Temp.