1. NIR Sensor Technology-Spectroscopy
Moving Grating-Scanning Monochromator
AOTF
MEMS
FTIR
Filter Photometer
Fixed Grating-Diode Array

2. 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

3. Types of NIR Spectrometers
Scanning Devices
Moving Grating-Scanning Monochromator
AOTF
MEMS
FTIR
Non-Scanning Devices
Filter Photometer
Fixed Grating-Diode Array

4. An avenue to avoid interference and ambiguity
Multiple-sensor detection (CCD’s, diode arrays)
An avenue to avoid interference and ambiguity

5. Sample The Sample is Moving! For the following unit operations:
Blending
Coating
Drying
Granulation
Roller Compaction
On-Line Content Uniformity
The Sample is Moving!

6. 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?

7. NIR Diode Array Specifications
Standard InGaAs – 1.7 micron
No of Pixels
Spectral Range nm
Resolution nm
128
6.5
256*
3.25
512
1.6125
1024
0.8
* Most popular choice

8. NIR Diode Array Specifications
Extended InGaAs – 2.2 micron
No of Pixels
Spectral Range nm
Resolution nm
128
8.8
256*
4.4
512
2.2
1024**
1.1
* Most popular choice **Not readily available

11. Other Desirable Features
Ruggedness
Diode Array spectrometers have no moving parts
Ease of use
Low Maintenance

12. 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

13. Instrument Rating Pentagon Score: 0 = low; 5 = high
Cost
Robustness
Index
Ease of use
Richness
of data
Speed of
Acquisition
fti
1998