Signals (Modular LC DAD)

You can define the characteristics of up to five signals (A to E) for the G1315A/B DAD, or up to eight signals (A to H) for the G1315C/D, G4212A/B, G7115A and G7117A/B DAD. The signal definitions also optionally include reference signals. You can define the center wavelengths and bandwidths of the sample and reference wavelengths for each signal. Mark the Acquire check box for each signal you wish to store.

For the HDR-DAD Cluster, up to 24 signals are produced: Up to eight DAD signals from the HDR-DAD Cluster. Note that the signal identifier for the combined signal from the HDR-DAD Cluster is the same as that for a single DAD. Up to eight LNG signals from the DAD with the long flow cell. Up to eight SHT signals from the DAD with the short flow cell.

Wavelength

The wavelength at which the absorbance of the sample is measured as a function of time. The absorbance at the reference wavelength is subtracted from the absorbance at the sample wavelength.

Limits

G1315A-D and G7115A	191 to 949 nm
G4212A/B and G7117A/B/C	190.0 to 640.0 nm
HDR-DAD	190.0 to 640.0 nm

The precision with which you can set the Wavelength depends on the CDS application.

Bandwidth

The bandwidth of the sample wavelength. The bandwidth determines the wavelength range over which the absorbance is measured. For example, a sample wavelength of 254 nm with a sample bandwidth of 20 nm measures absorbance from 244 to 264 nm.

Limits

G1315A-D and G7115A	2 to 400 nm (depending on the sample wavelength)
G4212A/B and G7117A/B/C	1.0 to 400.0 nm
HDR-DAD	1.0 to 400.0 nm

The precision with which you can set the Bandwidth depends on the CDS application.

Reference Wavelength

The wavelength at which a reference absorbance is measured as a function of time. Mark the check box to switch on the reference wavelength. The reference wavelength compensates for fluctuations caused by changes in baseline absorbance, for example due to changes in solvent composition during gradient elution.

Limits

G1315A-D and G7115A	191 to 949 nm or Off (no reference)
G4212A/B and G7117A/B/C	190.0 to 640.0 nm or Off (no reference)
HDR-DAD	190.0 to 640.0 nm or Off (no reference)

The precision with which you can set the Reference Wavelength depends on the CDS application.

Reference Bandwidth

The bandwidth of the reference wavelength.

Limits

G1315A-D and G7115A	2 to 400 nm, but dependent on the reference wavelength. Mark the check box to switch on the reference bandwidth. For reference wavelengths less than 390 nm or greater than 750 nm, the bandwidth is restricted to twice the difference between the reference wavelength limit and the reference wavelength value.
G4212A/B and G7117A/B/C	1.0 to 400.0 nm
HDR-DAD	1.0 to 400.0 nm

The precision with which you can set the Reference Bandwidth depends on the CDS application.