Gain factor

Hi alpha_go welcome to the Community!

I moved your question to the GC/MS Forum for better visibility.

Cheers,

Kristen

Enhancements to Gain Normalized Instrument Tuning: Understanding the Benefits and Features: December 21, 2007. 

5989-7654EN.pdf (SECURED) (agilent.com)

This is the paper that explains the details.

Webinar:  Optimizing Conditions for GC/MS Analyses (on24.com)

The very simplified answers:

From the online help in MassHunter Acquisition:

Gain Factor

An EM gain factor adjusts the signal sensitivity of the detector. EM gain factors have the advantage of remaining constant as the multiplier ages. Therefore, the use of a gain factor produces much higher signal reproducibility for any instrument and better consistency between instruments.

A gain factor of 1.0 represents a signal multiplication (gain) of 100,000 by the detector. Higher gain factors raise the signal sensitivity but can also decrease the life of the EM. Using a higher gain factor can also cause a nonlinear response for the upper range of the calibration curve. It is recommended that the lowest possible gain that allows achieving the desired detection limits be used.

Gain factor settings range from 0.3 to 25 for a single quadrupole.

The relationship between gain factor and EM Voltage is stored in the tune file and updated during tuning.

From the MSD_Familiarization Guide

 Gain Factor - If Gain Factor is selected in the EM Setting drop-down list, the Gain Factor can be specified here. An EM gain factor adjusts the signal sensitivity of the detector. EM gain factors have the advantage of remaining constant as the multiplier ages. Therefore, the use of a gain factor produces much higher signal reproducibility for any instrument and better consistency between instruments. 

Thank you very much for your quick answer. It's very important for me to understand the concept well, so I have some consistency problems with the response of the compounds.