Atlas Copco PowerMACS 4000, User Manual

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6.6.3 Monitoring Check
– Torque Rate
User Interface:
Parameters: Fatal , Monitoring buffer , T Start , T Stop , A Start , A Stop , TRL , TRH , Dev
Function: This function checks the Torque Rate (TR), i.e. the ratio of torque vs. angle.
Measuring is started when the angle
A Start has elapsed from that torque reached the
value T Start . This is point (A
1
, T
1
).
Point (A
2
, T
2
) is the point where measuring is stopped, that is, when any of the following
conditions first is met:
- when the torque reaches the value
T Stop
- when the angle measured from T Start reaches A Stop
- when the torque reaches final torque, that is, the end of the monitoring buffer.
This point is used only if both
T Stop and A Stop are empty.
T Start , T Stop , A Start , and A Stop are all optional. If T Start is left blank, then A Start is
measured from the start of the monitoring buffer. Leaving A Start empty is equal to setting
A Start to zero. Leaving T Stop and/or A Stop empty deactivates the respective check as
stop conditions.
The Torque Rate is calculated as:
TR = (T
2
– T
1
) / (A
2
– A
1
)
where T
1
, T
2
, A
1
, and A
2
are defined as in the diagrams below.
The measured TR is checked to be within the limits
TRH and TRL .
This function also checks that the torque does not deviate more than
Dev from a straight
line between the points (A
1
, T
1
) and (A
2
, T
2
). The Deviation in sample k, DEV(k), is