5
5.
Scanning bars
In this chapter, we briefly explain the scanning of bars with the ultrasound measuring device.
The bar has been divided by the middle and provided with drill holes then filled with lead. This
method is used frequently to fake silver bars using lead-tin alloys.
Preparation of measurement: Calibrating the BarScreenSensor
The first step consists of the calibration of the measurement unit by using the included stainless
steel measurement plate. The calibration should be done at least after every replacement of the
measurement head and/or the batteries. Apply enough coupling gel on the measurement head
and/or the stainless steel plate and press the measurement head on the test block on the device.
Press
CAL
to get to the calibration mode. Wait until the display shows 4.0 mm, which indicates
that the calibration has finished. After that, the device will turn back to the selected speed and
the measurement can begin.
Measurement 1: Testing with already known sound speed
1.) Establishing the speed value
We have summarized some values of the most important (precious) metals for you in an
overview that you can find in “6. Tips and tricks“. If you know the material you want to test, you
can read the values in this overview.
After starting the device, please adapt the sound speed in the menu by pressing the VEL-button.
You can now use the arrow keys up and down to switch between the saved sound speeds. If the
sound speed is close to your desired value, push the VEL-button again. This allows fine
adjustment oft he sound speed. In this example, we have selected 4329 m/s for the brass bar.
Summary of Contents for BARSCREENSENSOR
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