Firma:              Spectra Physics

Modell:                         SP 4290

Kommentar:     Dokumente engl.

Keypad

The SP4290 utilizes a three function keypad. The blue lower sec­tion of each key initiates a system function, while the upper por­tion represents numeric/punctuation characters (upper left) and alpha characters (upper right).

Dialog

The Dialog function allows the user to modify the file currently being addressed for edit. After pressing the DIALOG key, the operator is guided by a sequence of queries. These queries provide a step-by-step process for establishing the necessary file parameters for a particular analysis. The Dialog sequence used depends an the user's responses to the queries.

Data Reduction

The SP4290 integrates a number of functions and parameters designed to analyze and reduce the chromatographec data to the form most usable by the chromatographer. This section introduces these parameters and their implementation.

Component Window (CW) and Absolute Retention Time (RT)

The SP4290 uses retention time to determine whether or not peaks in the chromatogram are the same as those in the File. This is accom­plished by logically selecting peaks within a certain range or "window" of the retention time specified for each peak in the Com­ponent Table.

A window is determined for each component in the table based an its retention time value and the component window (CW) setting. (CW is entered out of dialog as a decimal fraction; its default value is 0.1.)

For example, if a Component Table RT value is 2 and CW is 0.1 (10%), the window for identification of the component is between 1.8 and 2.2. There is a CW value for each RRT Reference peak.

Time functions

Time functions are events that can be made to occur during or after a chromatographic run. Initiation of Time Functions can be accom­plished by either setting up a Time Function Table through Dialog, or by means of a Direct Command using the UN key.

Integration

The SP4290 makes logical decisions concerning peak detection, integration and baseline correction for all types of peaks. The purpose of this section is to provide the chromatographer with information that will allow him to understand the workings of the SP4290 peak handling. A thorough understanding of this section is necessary before changing peak detection parameters.

Options

The SP4290 supports option cartridges that are inserted into the receptacles located at the rear of the unit. These cartridges provide Second Channel and External Control capabilities.