Checkline TI-007DLX, Руководство по эксплуатации

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3. Press the key to perform the manual zero. “PRB0” will briefly be displayed
on the screen, indicating the zero calculation is being performed.
5.2 Material Calibration
In order for the TI-007DLX to make accurate measurements, it must be set to the
correct sound velocity of the material being measured. Different types of materials have
different inherent sound velocities. For example, the velocity of sound through steel
is about 0.233 inches per microsecond, versus that of aluminum, which is about 0.248
inches per microsecond. If the gauge is not set to the correct sound velocity, all of the
measurements the gauge makes will be erroneous by some amount.
The One Point calibration is the simplest and most commonly used calibration method
—optimizing linearity over large ranges. The Two Point calibration allows for greater
accuracy over small ranges by calculating both the probe zero, as well as the material
velocity. The TI-007DLX provides three simple methods for setting the sound-velocity
outlined on the following page:
Known Velocity
If the material velocity is known, it can be manually entered into the TI-00, rather than
have the TI-007DLX calculate the velocity value using a known thickness of the same
material type. The steps for entering the velocity are outlined below:
1. With the transducer free from contact with the material, press the key to
display the current velocity.
2. Use the and keys to scroll the velocity to the known target
value.
NOTE: The longer the keys are pressed and held, the faster the value will
increment/decrement.
NOTE:
Pressing the key prior to pressing the key will abort the cal
routine without saving any changes.
3. Press the key to set the velocity value and return to the measurement
screen. The new velocity value will be shown at the top of
the display.
Known Thickness
Often times the exact sound velocity of a material is unknown. However, a sample
with one or two known thicknesses can be used to determine the sound velocity. As
previously discussed, the TI-007DLX has a one or two point calibration option. The
one point calibration option is most suited for linearity over large ranges. When using
the one point option, the calibration should be perform on the thickest side of the
measurement range for the best linearity for that range. For example, if the measurement