Dakota Ultrasonics MINI--MAX User Manual

Page 87

MINI-MAX Ultrasonic Bolt Tension Monitor

Evaluate the Error: Compare the difference between the physical and

ultrasonic lengths. If the error exceeds 0.0005” the temperature must be

adjusted, and the CAL procedure repeated for 3” & 6” bars – Setting Up the

MINI-MAX for Measurement.

Note: This shouldn’t be necessary when using the glass block as the

calibration standard.

Calculating Temperature Adjustment: Use the difference between the

physical and ultrasonic lengths of the 6” bar only and multiply the error by 3.

This is the same as OVER correcting the error by 300%.

[(Ultrasonic Length 6” Bar) – (Physical Length 6” Bar)] * 3

example using the equation above:

[ ( 6.0077 ) – ( 6.0049 ) ] * 3 = 0.0084”.

The over corrected error must now be subtracted from the physical length

of the 6” bar: 6.0049” – 0.0084” = 5.9965”

26) Press the MEAS key once to activate measure menu items. Press the

MEAS key multiple times to move right and the ESC key multiple times

to move left until the TEMP cell is highlighted.

27) Use the LEFT and RIGHT arrow keys to scroll the temperature value

until the measured value is reading the over corrected value calculated

above.

Note: Lower temperatures will make the bolt read longer, and higher

temperatures shorter.

28) Repeat steps 14 – 25 above to re-calculate the zero value using the

adjusted temperature setting.