The Olis Digital Subtractive Method of acquiring CD is "better" than traditional CD acquisition.
Among many other things, the Olis DSM CD spectrophotometers:

- Collect the correct answer without calibration
- Experience no electronic drift
- Require no system changes over 10,000 fold signal strength variance
- Produce flat baselines
- Use 100% more light than single beam systems
- Collect real-time reference
- Operate as a high end dual beam absorbance spectrophotometer
- Utilize fully digital data acquisition and noise reduction

The Olis DSM CDs provide higher sensitivity, shorter collection times, and superior data analysis facilities when compared with every single beam (lock-in amplifier dependent) CD.

After introducing the model 1000 in 1996, we added lower cost models with all the benefits of the proven 1000, less rapid- scanning detection.  In 1998, we introduced the model 16 as our double prism model, supporting a scan range of 165-700 nm. The model 17 was selected as our prism + grating model, supporting 185-1100 nm.  In 2000, these were joined by a small double grating monochromator with a spectral range of 170-700 nm: the Olis DSM 10.

Today¡¯s data are an eclectic assortment of runs made on Olis CD spectrophotometers. Results above 185 nm are identical among the units. Results below 185 nm to approximately 167-170 nm are achievable by the models RSM 1000, Olis 16 and 10. Results including rapid-scanning (not shown in this collection of results) are possible only with the Olis RSM 1000 monochromator. 

Circular Dichroism wiht RSM1000

Summary of important facts about the Olis dual-beam CDs