Waters 2489, Operator'S Manual

Page: 88 / 234

3-20 Preparing the Detector
Operating the Trace and Scale functions
The Trace function allows you to display an absorbance trace for the last n
minutes (up to 60) of detector operation.
• When you press the TRACE key, the detector displays the absorbance
acquired over the last 30 minutes by default. It updates the trace once
every 20 seconds.
• When you press the Scale key (Shift TRACE), the detector displays the
scaled trace with T1 (ending time) displayed (–30 for the last 30
minutes) by default.
You can change the ending time parameter to any number from 1 to 60.
You can use the Scale function to “zoom” in on a particular section of the
trace.
To display the Scale parameters after you press the Scale key:
1. Press Next to display T2 (starting time). The default is 0.
2. Press Next again to display AU1 (starting or low absorbance). The
default is auto.
3. Press Next again to display AU2 (ending or high absorbance). The
default is auto.
By entering appropriate times and absorbance numbers in the four
scaling parameter boxes, you can zoom in on one section of the current
absorbance trace.
• For AU1 and AU2, press CE to reset to auto.
• T1 represents the left-hand side of the trace, or ending time to be
displayed (default is –30).
• T2 represents the right-hand side of the trace, or starting time
(default is 0).
Minimum
ratio 5 (of 5) Numeric None 0.00 to 999.99 0.00
Maximum
ratio 5 (of 5) Numeric None 0.00 to 999.99 2.00
Primary and secondary function (method) parameters
Function Screen Type Units Range Default