# Pitch Change

This strategy verifies the first point along the trace where the slope change not more than the specified slope change parameter. The trace is analyzed between the range from Residual Angle Threshold 2 to Residual Angle Threshold 1.

Parameter | Description
--- | ---
Inspection Name | Name of the inspection.
Torque correction coefficient | When extensions are used, the wrench measurement must be compensated to show a more accurate torque value. To calculate the correction coefficient, please refer toHow to calculate the Torque Correction Coefficient. When extensions are not used, Torque correction coefficient = 1.
Angle correction coefficient | When extensions cause additional wrench bending, the wrench angle measurement must be compensated to show a more accurate angle value. To calculate the correction value, please refer to How to Calculate the Angle Correction. When extensions are not used, Angle correction coefficient = 0.
Number of sample | Number of tests to run inside the inspection. Maximum value: 1000. If Number of sample = 0, the number of tests is infinite. If Number of sample > 1, batch result OK only if all tests are OK.
Cycle start | Torque value from which the test operation starts. The Cycle start must be ≤ Final angle monitoring torque value, and must be ≥ smartHEAD Min load value. If Cycle start = 0, its value is automatically set to the smartHEAD Min load value.
Minimum torque limit | Minimum torque value that must be reached within the Target angle value in order to get an OK result.
Maximum torque limit | Upper torque limit value.
Change screw | If the torque applied reaches this limit, the message Change screw is shown on the wrench display. Must be > Maximum limit torque. The Change screw must be equal or higher than the Maximum limit torque.
Target torque | Torque target value.
Torque tolerance | Tolerance that defines the maximum torque and the minimum torque according to the Target torque previously specified. Value is expressed in percentage (%).
Final angle monitoring torque | Torque value from which the angle measurement starts (usually set to 50% of the Target torque). If Final angle monitoring torque = 0, its value is automatically set to Cycle start value.
Control mode | Method to define the torque limits from the following options: Min/Max: the torque lower and upper limits are the values entered for the parameters Minimum torque and Maximum torque. Target/Tolerance: the torque lower and upper limits are calculated according to the values of the parameters Target torque and Torque tolerance.
Residual angle threshold 1 | Maximum angle value (measured from the Final angle monitoring torque) for the residual torque when the residual torque is lower than the breakaway point.
Residual angle threshold 2 | Maximum angle value (measured from the Final angle monitoring torque) for the residual torque when the residual torque is lower than the breakaway point. The Residual angle threshold 2 must be higher than the Residual angle threshold 1 .
Slope change | Detect residual torque by tracking changes in angle during final tightening. It works whether the breakaway point and residual point are at the same place or not. Default value: 2.00. Minimum value: 0.01. Maximum value: 100.0.
Ratchet time | Starts when the torque goes below the Cycle start without reaching the 3rd percentage value. This allows the operator to release the torque for a while and recharge during the tightening operation. Default value: 0.1 sec. Minimum value: 0.1 sec. Maximum value: 30 sec.

Curve progression representing gradient change between the measurement interval with breakaway
Curve progression representing gradient change between the measurement interval without breakaway

T0 | Final angle monitoring torque | T1 | Minimum torque
a1 | Residual Angle Threshold 1 | a2 | Residual Angle Threshold 2

Results:

The result is the first point where the slope changes more than the allowed limit within the specified angle range.