HEIDENHAIN ND 2100G - Manual (Page 93)

ND 2100G GAGE-CHEK 93
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p UCL and LCL
The UCL and LCL fields are displayed when the subgroup size is 1.
Subgroup sizes greater than 1 change the lower half of the SPC screen
to display mean and range control limits that are described later in this
section. By default, the UCL and LCL fields display the Upper and
Lower Control Limits specified earlier on the Tolerances setup screen.
The limits are used by the ND 2100G graphing software to scale the
value axis of SPC graphs.
x, r Ucl and Lcl
The x Ucl and Lcl and r Ucl and Lcl fields are displayed when the
subgroup size is greater than 1.
Ucl and Lcl
The x Ucl and x Lcl are the likely limits of the values of x in future
subgroups. These limits are either entered manually or calculated,
using the RECALC soft key, on the basis of existing subgroup data.
The x Ucl and x Lcl values are displayed as horizontal lines on the x
chart and used to generate SPC limit alarms.
To manually specify x Ucl and x Lcl limits:
U Highlight the x Ucl or x Lcl field
U Use the numeric keypad to enter the desired x Ucl or x Lcl
U Press the ENTER key
Recalculating x Ucl and Lcl
Once subgroup data has been collected, the upper and lower control
limits can be simultaneously recalculated.
To recalculate x Ucl and x Lcl:
U Highlight the x Ucl field
U Press the RECALC soft key
U Press the ENTER key. Both the x Ucl and x Lcl are recalculated
The UCL and LCL values shown on the SPC setup screen
should not be altered after initial setup. Change them only
if you are certain that your application requires different
values.