Response time describes how fast the detector signal follows a sudden change of absorbance in the flow cell. The detector uses digital filters to adapt response time to the width of the peaks in your chromatogram. These filters do not affect peak area nor peak symmetry. When set correctly, such filters reduce baseline noise significantly ( Influence of Response Time on Signal and Noise), but reduce peak height only slightly. In addition, these filters reduce the data rate to allow optimum integration and display of your peaks and to minimize disk space required to store chromatograms and spectra.
Peak Width — Response Time — Data Rate (G7115A/G7165A) list the filter choices of the detector. To get optimum results, set peak width as close as possible to a narrow peak of interest in your chromatogram. Response time will the be approximately 1/3 of the peak width, resulting in less than 5 % peak-height reduction and less than 5 % additional peak dispersion. Decreasing the peak width setting in the detector will result in less than 5 % gain in peak height but baseline noise will increase by a factor of 1.4 for a factor of 2 response-time reduction. Increasing peak width (response time) by factor of two from the recommended setting (over-filtering) will reduce peak height by about 20 % and reduce baseline noise by a factor of 1.4 . This gives you the best possible signal-to-noise ratio, but may affect peak resolution.
| Peak width at half height [min]Values in the user interface may be rounded | Response [s] | Scan data rate[Hz] ≤ 251 pts/scan | Scan data rate[Hz] ≤ 501 pts/scan | Scan data rate[Hz] > 501 pts/scan |
|---|---|---|---|---|---|
< 0.0015625 | 0.015625 | 120 | 120 | 40 | 20 |
> 0.0015625 | 0.03125 | 120 | 120 | 40 | 20 |
> 0.003125 | 0.0625 | 80 | 80 | 40 | 20 |
> 0.00625 | 0.125 | 40 | 40 | 40 | 20 |
> 0.0125 | 0.25 | 20 | 20 | 20 | 20 |
> 0.025 | 0.5 | 10 | 10 | 10 | 10 |
> 0.05 | 1 | 5 | 5 | 5 | 5 |
> 0.1 | 2 | 2.5 | 2.5 | 2.5 | 2.5 |
> 0.2 | 4 | 1.25 | 1.25 | 1.25 | 1.25 |
> 0.4 | 8 | 0.625 | 0.625 | 0.625 | 0.625 |
> 0.85 | 16 | 0.3125 | 0.3125 | 0.3125 | 0.3125 |
[1]Values in the user interface may be rounded
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id: 3358190859