Extech Instruments
16 TKG250- EN V2.4 11/13
3 Calibrating the Gauge and Making Measurements
Calibrating is the process of adjusting the gauge for a specific material and transducer
before testing material to make sure that all measurements are accurate. You must always
calibrate before measuring material for standard accuracy.
To measure a thickness of unknown material you need to know the velocity of the sound
in the unknown material. To find the velocity of the sound you can use one of the
following methods:
Velocity calibration only
Velocity and zero calibration
Zero calibration only
Delay line calibration
Velocity Calibration Only
If you are working with a test piece of known thickness but unknown material, then you
can calibrate the velocity of the sound in the unknown material by measuring the time of
flight from main-bang to the first back echo. By using the known thickness you can
calculate velocity of the sound for the unknown material.
To perform any calibration, first go to the measure mode and press Menu/OK. Then go to
the Cal option in the Menu screen and press OK. The following Cal mode screen should
appear. To exit the cal screen without performing any calibration, press OK. To proceed
to velocity cal, follow the following instructions.
Cal screen for non-datalogger version
While measuring the thicker step, select VEL by pressing F3. After selecting VEL, you
can take the transducer off the test block. If the displayed measurement is different than
the known value of the step, use the up or down arrow key to adjust the displayed value
to the known value of the step. Press OK to perform the calibration. The unit will briefly
display the calibrated velocity value in the top of the screen and then return to measure
mode.
Содержание TKG250
Страница 1: ...USER GUIDE Model TKG250 Ultrasonic Thickness Gauge ...
Страница 41: ...TKG250 Ultrasonic Thickness Gauge 41 ...
Страница 71: ...TKG250 Ultrasonic Thickness Gauge 71 F1 F3 ...