New: V5.1 Diagnoses Background for Misalignment, Dirty water or windows, etc. and guides acceptance.
For all those users of our LISST-100X series instruments who have asked, after collecting a background file: should I accept and save, here is help.
This recently released Version 5.1 of the LISST-SOP software grabs a background file, as before, and then – and this is new – evaluates it, i.e. it checks if laser output is within spec, if optics are in alignment, if windows are clean, if the water you used was clean, and if scintillation due to temperature microstructure in the cell contaminated the background data. The software then makes suggestions on whether to accept the file, or collect a new file for specified reasons and with specified cures, e.g. clean the windows, or use cleaner water. In this way, this release helps you to acquire the best possible background file.
The background scattering measurement is critical to good instrument performance. It is especially critical for applications where the optical transmission may be greater than 90%. The new software will help you get there.
| Fig 1. Example of new background quality control messages. Left: background passes automated checks. Right: background failed quality control checks, the most likely cause of failure is displayed on the screen along with a message describing how to resolve the issue. |
New Functionalities: The most difficult part of collecting a background measurement is preventing contamination of the measurement. Background measurements are often contaminated by: dirt or films on the windows, bubbles or particles in the background water, or temperature fluctuations in the water which can arise if the water and instrument temperatures are different (always allow time to equalize temperatures). Previous versions of the SOP software offered no help with diagnosing these potential problems . In this update the background data is automatically checked for the most common indicators of background contamination. If the software detects a problem with the background, it suggests the best way to correct the issue. For example, it may suggest cleaning the windows, or allow the background water to degas for a longer period of time, or allow temperature to reach equilibrium. These messages are displayed clearly along with the display of the newly acquired background. This is designed to reduce the user’s anxiety in accepting or repeating a background file.
In addition to background quality control, this software release now verifies that you have the proper instrument files (factory zscat, ring area, InstrumentData.txt, and LISST.ini) before launching the main program. If they are missing, a new tool helps you to locate them and place them in the appropriate folders. However, this should only occur if there were errors in the installation process or if LISST files were deleted from the computer.
Installation: The LISST-SOPv5.1 installer comes in two flavors. A full installer allows you to install a fresh copy of the software on your machine, and an update installer which allows you to update your existing installation of the LISST-SOP software. The update installer will preserving your instrument specific files already on the computer from the previous installation.
Download: LISST-SOPv5.1 can be downloaded from the LISST-100X product page. Choose the Software & Download section and select either Update or Full installer. More details on upgrading to LISST-SOP v5.1 can be found here.