The optical unit of the 79853C Variable Wavelength Detector (VWD) has been modified to overcome wander problems due to temperature variations of the lab environment.
This service manual details the enhanced optical unit for Agilent's 79853C Variable Wavelength Detector, introduced in June 1995 to improve performance under temperature variations. It covers compatibility with previous units, part numbers for the new design, and step-by-step procedures for replacing components like the entrance slit and standard flow cell. The manual includes safety warnings, required tools, and calibration steps to ensure proper optical alignment.
The enhanced unit, marked with 'D', requires specific parts and firmware to function correctly. It is backward compatible with earlier models, but some components are not interchangeable. The document also references related service handbooks and provides identification methods for the new optical unit.
| Introduction Date | June 1995 |
|---|---|
| Firmware Revision | 4.31 |
| Part Number for Standard Flow Cell | 79853-60000 |
| Prefix for Enhanced Unit | 3522 J 04305 and above |
The 'D' unit has redesigned components including a new mirror #1 assembly with a plane mirror, redesigned entrance slit holder, and new beam splitter assembly. It is more stable under temperature variations.
The enhanced optical unit requires firmware revision 4.31, which is different from the 4.24 revision used with the original 'C' unit.
The new standard flow cell (Part number 79853-60000) is required when replacing the 'C' optical unit with the 'D' unit.
You can identify the enhanced optical unit by its prefix (3522 J 04305 and above), firmware revision 4.31, a label reading 'ENHANCED ILLUMINATION SYSTEM', or a handle on the reference slit that protrudes from the cover plate.