Dakota Ultrasonics MINI--MAX User Manual

Page 89

MINI-MAX Ultrasonic Bolt Tension Monitor

33) Place the transducer on the 3” bar in the exact location as before.

34) Press the ENTER key to save and document the current reading in the

highlighted cell location.

35) Repeat steps 33 & 34 for the 6” bar in location A2. Note: Repeat the

steps an additional time for the extra point on the glass block.

Note: The Mini-Max is now properly zeroed and ready for action.

This next section demonstrates how to go back and verify if the probe zero value
is still linear and “In Spec” at a later time. It’s important to note that user should
never have to change or re-calculate the probe zero value again, unless the
MINI-MAX, transducer, or cable has been replaced. If the transducer or cable
has changed, and the probe zero value re-calculated, the change in the zero
value should be very small. Therefore, if the zero is re-calculated and the delta is
very large, something else has gone wrong and the user should become
suspicious of the how well the probe zero was performed.

If we consider the initial probe zero value constant, as the hardware cal bars or
glass block have not been replaced, the future verifications should always show
an elongation value of +/- 0.0001”, in order to be considered “In Spec”. If the
probe zero is out of spec, the user should make adjustments only to the physical
temperature setting in the MINI-MAX. In other words, the primary reason the
probe zero is out of spec is because the physical temperature of the probe zero
calibration standards has changed. If the accessory temperature sensor is
being used, the sensor will automatically adjust the physical temperature
and the MINI-MAX should be “In Spec” and displaying an elongation value
of 0.0000” +/- .0001”. The next section outlines the verification procedures.

Verifying the Probe Zero at a Later Time

1) Press the MENU key once to activate the menu items tab. Press the

MENU key multiple times to tab right, and the ESC key multiple times to

tab left, until the DATA menu is highlighted and displaying the submenu

items.