MMX-6 DL Ultrasonic Thickness Gauge
6)While the transducer is firmly coupled to the probe-disc, press the PRB-0key on the keypad. The MMX-6 DL will display "Prb0" while it is calculating its zero point.
7)Remove the transducer from the probe-disc.
At this point, the MMX-6 DL has successfully calculated it's internal error factor, and will compensate for this value in any subsequent measurements. When performing a "probe-zero", the MMX-6 DL will always use the sound-velocity value of the built-in probe-disc, even if some other velocity value has been entered for making actual measurements. Though the MMX-6 DL will remember the last "probe-zero" performed, it is generally a good idea to perform a "probe-zero" whenever the tool is turned on, as well as any time a different transducer is used. This will ensure that the instrument is always correctly zeroed.
Calibration
In order for the MMX-6 DL to make accurate measurements, it must be set to the correct sound-velocity for the material being measured. Different types of material 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 tool is not set to the correct sound-velocity, all of the measurements the tool makes will be erroneous by some fixed percentage. The one point