Dakota Ultrasonics
At this point, the MX-5has successfully calculated it's internal error factor, and will compensate for this value in any subsequent measurements. When performing a "probe-zero", the MX-5will 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 MX-5will remember the last "probe-zero" performed, it is generally a good idea to perform a "probe-zero" whenever the gauge 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 MX-5to 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 gauge is not set to the correct sound-velocity, all of the measurements the gauge makes will be erroneous by some fixed percentage. The one point calibration is the simplest and most commonly used calibration procedure - optimizing linearity over large ranges. The two point calibration allows for greater accuracy over small ranges by calculating the probe zero and velocity. The MX-5provides three simple methods for setting the sound-velocity, described in the following pages.
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