SureCal Automated System Calibration System

The Sure_Cal(*) technology is a method for achieving a standard Raman spectrum that has both short and long term precision and accuracy. It allows the collection of the standard spectrum which is independent from typical instrument instabilities. The Sure_Cal technology simultaneously measure Raman spectrum of sample, laser/neon spectrum and neon spectrum. An Integral Transform Process is employed to correct Raman data for instrument instabilities. Transform result produces a Raman spectrum, which is Automatically calibrated in both frequency.

Figure 1: The measured spectra of the Raman Neon and Laser/Neon are split up so that they occupy different portions of the CCD detector. The Laser is combined with Neon so that an accurate frequency position can be determined. A separate channel for Neon is measured at the same resolution as the Raman channel to correct for the "breathing effects" of the system. The Laser/Neon is measured at a factor of two higher resolution than the measured Raman spectrum so that the accurate and precise position of the laser line can be determined.

Figure 2: Sure_Cal frequency performance. Frequency precision - 0.018cm^-1 RSD. Toluene Over 15 Hours, One Spectrum Every 5 Minutes 45 Second Integration @ 38mW.

Benefits of Sure_Cal

• The automated Raman frequency calibration has precision and accuracy
• Reliable and reproductible detection of small Raman shifts, e. g. stress induced line shifting, protein folding
• High quality subtraction of Raman spectra
• Improved chemometrical results
• Facilitates spectrum search in digital libraries