Instrument Type:

Detector

Related Command:

Trigger

Description:

Delta is a signal property that is accessible (read-only) via the Log command. Delta indicates the difference between the current signal value and the value measured one second ago.

Delta is especially useful when creating complex trigger conditions. A peak cannot only be recognized by the height of its absorption signal within a chromatogram, but also, for example, by a sharp increase of the signal.

 Note: 

The delta is calculated once per second independent of the Sampling Rate or the Step used for data acquisition.

Function:

Delta is used especially for trigger conditions. The syntax is as follows:

<Signal.Delta><comparison operator><value>

Example:

Trigger PEAK UV_VIS_1.Delta > 0.1

Sound Frequency=440, Duration=1

EndTrigger

With this program, an acoustic beep sounds after a peak has been detected (exactly: if the UV_VIS_1 signal ascends by more than 0.1 mAU in one second).

Note:

Windows XP (64 bit), Windows Vista and Windows 7 operating systems do not support the Sound command.

 Tip: 

Select the reference value individually depending on the peak height and the baseline noise.

 Tip:

For another example of a trigger condition, refer to  Trigger Commands.