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Alliance compression check failure with 200-µL sample loop installed - WKB25932

Article number: 25932

SYMPTOMS

ENVIRONMENT

  • Alliance 2695 Separations Module

CAUSE

Compressible volume is increased when conducting the compression test with larger sample loops.

  • The parameters for the compression test were much too tight at anything below 20-psi delta decay with the larger sample loop.

FIX or WORKAROUND

  1. Adjust the compression test parameters according to the default parameters recommended in the operators guide.
    • Recommendation: use a max delta decay of 50 psi as the default.
    • Change other parameters, such as the target compression pressure, only as necessary when working with larger sample loops and/or different solvent compressibility.
  2. Review the compression test guidelines outlined in the following operator's guides:

Compression Check Diagnostic Parameters.jpg

ADDITIONAL INFORMATION

Compression test passed with repeatable results with the 200-µL sample loop when delta decay was 50 psi and target compression pressure was 200 µL. This is within the acceptable range of parameters for characterizing the instrument using this diagnostic.

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