2 probe zero, Performing an auto probe zero (off block) – Dakota Ultrasonics CMX DL User Manual

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CMX

High Performance Material & Coating Thickness Gauge

6.2 Probe zero

The next step is to perform a probe zero. The zero function is a very important and
necessary function that must be done prior to calibration. It should be done on a
regular basis. In fact, the CMX

has been programmed to force this issue at regular

intervals during operation if it hasn’t been done. If the CMX

is not zeroed correctly,

all the measurements taken may be in error by some fixed value. When the CMX

is using the auto zero (electronic zero), the CMX

can be in any measurement

mode. However, when the manual zero is being used, the CMX

must be in pulse-

echo mode in order to perform the zero. The CMX

will also see to it that this

occurs by simply forcing the gauge into this mode when zero. Therefore, if the
CMX

is in the echo-echo measurement mode and a manual zero is being

performed, the CMX

will put the gauge into pulse-echo mode automatically before

performing the zero. While this is a very convenient feature of the CMX

, the user

should be sure to check the measurement mode following calibration to be sure the
CMX

is in the desired mode. The following steps outline both of these techniques.

The CMX

is equipped with two zero options:

1) Off Block Zero (Automatic Probe Zero) – When this feature is enabled the

CMX

will do an electronic zero automatically, eliminating the need for a zero

disk or block.

2) On Block Zero (Manual Probe Zero) – When this feature is enabled the

transducer must be placed on the probe zero disk (battery cover located on the
top of the unit.

Both zero procedures are outlined as follows:

Performing an Auto Probe Zero (Off Block)

Coating Probe Identified Coating Probe Not Identified

1) Be sure all couplant has been removed from the face of the transducer.