Auto Zero/Calibration - DAKOTA ULTRASONICS MiniMax v2.0 Operation Manual

Ultrasonic bolt tension monitor

Table of Contents

Dakota Ultrasonics

1) Press the

Group List Items until CREATE NEW GROUP? is highlighted.

2) Press the

confirmation screen.

3) Press the

New Group setup and return to the DATA menu.

4) Press the

reference lengths.

8.4 Auto Zero/Calibration

The auto calibration feature uses a single calibration bar and two multiples (echo-

echo mode) of the calibration bar to perform an automatic Two-Point calibration. If a

3" calibration bar is used, it would measure at 3", and then again on the second

multiple at 6". This zero option will typically be the preferred option, as it's the easiest

option to use and for the most part is automatic in terms of operation. However,

depending on signal quality and calibration standard used, may not always work. If

valid signals cannot be acquired during the auto set routine, the MiniMax will report

"Can't find stable echo". Before eliminating this option altogether and using one of

the manual options listed below, try relocating the transducer to various positions on

the end of the calibration standard first. Since the calibration standards are

cylindrical, they can sometimes create substantial sidewall noise, based on the the

length, transducer size, and frequency. Moving the transducer to the edge of the

cylinder will often times eliminate the noise by shooting down the edge of the

standard and allowing the MiniMax to acquire a reasonable signal.

Now that the bolt group CAL DATA has been created in the previous section, we're

ready to get started with the automatic zero/calibration process. The first thing to

note is the procedures in this section demonstrate a Two-Point calibration, but a very

fast and efficient one, with minimal adjustments required from the operator.

Measuring Calibration Standard – For the First Time

and

arrow keys multiple times to scroll through the new

key to accept the group parameters, and activate the

key to save the New Group, or the

key to return to the measurement screen to begin measuring

key to cancel the

Table of Contents