Instrument Type:

UltiMate and UltiMate 3000 micro pumps

Related Commands:

Hold

Continue

StopFlow

Description:

The ParkPercentage command enables the peak parking functionality. A peak can be parked only from the system if the ParkPercentage is > 0.00.

For the UltiMate pump, an external signal must be sent to the pump's START IN input.

For the UltiMate 3000 micro pumps, the ParkPercentage can be controlled via the corresponding commands, e.g., via script buttons on a panel. For example, one button sets ParkPercentage = 5 and the other ParkPercentage = 100.

If peak parking is signaled, e.g., via a digital impuls from a Mass Spectrometer, you can use triggers for one of the pump's inputs:

Function:

Peak parking is similar to the behavior of the StopFlow command:

• The Gradient program is interrupted.

• Usually, the flow is reduced (but not turned off).

However, unlike the behavior of the StopFlow command:

• Data Acquisition (see Acquisition On/Off) is not interrupted.

• A running Batch is not stopped.

The PeakParked variable displays the peak parking state. Chromeleon cannot control the state.

By parking a peak, the peak is slowly pumped through the detector. Thus, you can operate, for example, a Mass Spectrometer in a more sensitive range.

 Tips: 

Peak parking freezes the gradient with its current composition and reduced flow while data acquisition continues. Please keep the following in mind::

• The retention times do not correspond to the expected times.

• Audit Trail entries and gradient plots are no longer synchronized.

• Triggers may no longer work as programmed.

• Detection parameters need to be corrected.

• The Delay Time between two detectors is incorrect.

The changed flow is not displayed on the pump display or in Chromeleon.