User`s guide

Chapter 5 Optimizing Instrument Settings
5-68 PerSeptive Biosystems
5
Optimizing Delay
Time
NOTE: If you are analyzing a broad mass range and need
optimum resolution in all mass regions, you may need to
acquire smaller portions of the mass range and set the
Delay Time to optimize resolution for each mass range.
To optimize Delay Time:
1. Open a standard .BIC file for the mass range you are
acquiring. For more information, see “Selecting a .BIC
file” on page 5-8.
2. Acquire a spectrum and observe the resolution. For
information, see Section 6.5.2, Calculating Mass
Resolution.
If the resolution is not acceptable, increase the Delay
Time by 100 nsec (Linear mode) or 50 nsec (Reflector
mode), acquire a spectrum and observe. Leave the Grid
Voltage% setting unchanged.
If the signal is saturated at the higher Delay Time
setting, decrease the laser intensity and acquire a new
spectrum. If the signal decreases at the higher Delay
Time setting, increase the laser and acquire a new
spectrum.
Hint: If you are analyzing a mixture and the resolution
of the peak of interest is not acceptable, observe the
resolution of a higher mass peak and a lower mass
peak. If resolution is better on the higher mass peak,
decrease the Delay Time (by 100 nsec for Linear mode or
50 nsec for Reflector mode). If resolution is better on the
lower mass peak, increase the Delay Time (by 100 nsec
for Linear mode or 50 nsec for Reflector mode). Collect a
spectrum and observe. Leave the Grid Voltage% setting
unchanged.