6.2 Operation of split flow box software

All MFC are under automated control via the StaggerCon software installed on the Lonestar. The StaggerCon software should be launched once the Lonestar software is running. It will connect automatically after 60 seconds. Upon launch, the software displays the interface shown below.

StaggerCon user interface

For operation, flows and timings for each MFC (mass flow controller) are set in the box on the far right hand side. A close up is shown below where a MFC is set to a flow rate of 90 ml min‑¹ at 0 seconds and to a flow rate of 0 mL min^-1 after 60 seconds.

Flow and time control bo­x

Readbacks are given in the coloured boxes to the left. The blue box is a read-back of the MFC set point, as set by the software. If a delayed flow start time is set this blue box will read back 0 until the trigger is sent. The orange box displays a real-time read back from the MFC, as shown in Figure 6. In this example a flow of 0 mL min -1 will be set until 300 seconds elapses at which point a flow rate of 111 ml min-1 will be set.

MFC read backs

A delay can also be set on the Lonestar software sample acquisition. This time is set in the ‘Trigger Out Delay’ box on the StaggerCon interface, as shown below. This could be used in an application where the analyte of interest is not observed until more than one DF matrix has been collected. Delaying the acquisition start time can reduce the amount of redundant data collected.

Data acquisition delay set box

The software will automatically load the last method saved. StaggerCon methods can be saved using the ‘save config’ button at the bottom on the screen as shown below.

Save Config button

N.B. Saving a new configuration will overwrite the previous saved configuration.