NIR Sensor Technology-Spectroscopy
• Moving Grating-Scanning Monochromator
• AOTF• MEMS• FTIR• Filter Photometer• Fixed Grating-Diode ArrayFixed Grating-Diode Array
Acquisition Time
• FTNIR ~ 8 seconds• AOTF~10 seconds• NIR Diode Array~1 sec or less• Scanning Monochromator~30
seconds • 50 X 20 msecs = 1 sec
In presentation by Martin Warman, Pfizer, Inc. at IFPAC 2004
Types of NIR Spectrometers
• Scanning Devices• Moving Grating-
Scanning Monochromator
• AOTF• MEMS• FTIR
• Non-Scanning Devices
• Filter Photometer
• Fixed Grating-Fixed Grating-Diode ArrayDiode Array
Multiple-sensor detection (CCD’s, diode arrays)
An avenue to avoid interference and ambiguity
SampleFor the following unit operations:
1. Blending
2. Coating
3. Drying
4. Granulation
5. Roller Compaction
6. On-Line Content Uniformity
The Sample is Moving!
Resolution & Spectral Range
•How much resolution do you need?
•What are spectral signatures of the materials you are looking at typically in the NIR spectral range?
•What spectral range is adequate?
NIR Diode Array Specifications
No of Pixels Spectral Range nm
Resolution nm
128 900-1700 6.5
256* 900-1700 3.25
512 900-1700 1.6125
1024 900-1700 0.8
Standard InGaAs – 1.7 micron
* Most popular choice
NIR Diode Array Specifications
No of Pixels Spectral Range nm
Resolution nm
128 1100-2200 8.8
256* 1100-2200 4.4
512 1100-2200 2.2
1024** 1100-2200 1.1
Extended InGaAs – 2.2 micron
* Most popular choice **Not readily available
Other Desirable Features
•Ruggedness
•Diode Array spectrometers have no moving parts
•Ease of use
•Low Maintenance
Unique Features of CDI NIRS Automated built in references for wavelength
and amplitude, can add customer specific references
Do not have to remove from vessel to do OQ, can be done on the fly, even during experiment
Meets USP 1119 specifications-generates report
Dual redundant light source All in one package, Class I Div II, EP available
Instrument Rating PentagonScore: 0 = low; 5 = high
Cost
Robustness Index
Ease of useRichnessof data
Speed ofAcquisition
1998
1998