| Author | Message | ||
     Jae |
We are considering to purchase a NIR system for research and evaluation of wheat quality. I found DA 7000 VIS/NIR System through Perten company web page. I would greatly appreciate if some researchers give me information on the performance of this NIR system. Specifically, I am wondering if it is possible to scan wheat single kernel and dough using DA 7000 VIS/NIR System/Fiber Optic Accessories. I would also appreciate any information on other NIR systems that have similar function. | ||
| Gabi Levin |
Dear Jae, The measurement of bulk wheat grain and dough is absolutely feasible with our Luminar 3030 spectrometers, see our web site www.brimrose.com. It will also be possible to do single kernel analysis with our Luminar 3076 Seed Meister. If you provide me with more information on where to contact you, we can expand on this more. Looking forwrad to hear from you, Gabi Levin Brimrose Corp. of America 410 931 7200 | ||
| W. Fred McClure (Mcclure) |
Jae, If you will contact me by phone, I will be pleased to share my experiences with you. Mac (919) 515-6764 | ||
| Bruce H. Campbell (Campclan) |
Jae, If you want to explore more suppliers, look at the equipment section of this list server for a fairly complete listing. Bruce | ||
| Kent |
Maybe someone has had experience they could share about diode array versus AOTF NIR instruments for NIR analysis. They both cover the NIR region, incorporate a no moving parts design, and have relatively fast acquistion times. What would be the pros and cons for Jae? | ||
| hlmark |
I've used AOTF although I haven't actually used a diode array system. But there's one difference I can think of: with an AOTF you can predisperse the wavelengths (i.e., before the sample) whereas with a diode array you have to pass the full source spectrum through the sample, and disperse the wavelengths afterward. Thus a diode array system would be contrainidcated if the sample is heat or photo-sensitive. Howard | ||
| Gabi Levin |
On AOTF vs. Diode - AOTF from Brimrose, besides being pre-dispersed, provides also dual beam operation giving you real time ratio operation, as well as very high frequency modulation with ambient light rejection of 10(exp+6)allowing you to operate with complete disregard to ambient light variations. To the best of my knolwedge, diode arrays do not provide real tiem dual beam, nor do they offer modulation at frequencies far from the possible naturally occuring ambient light variations. For more information please e-mail to [email protected] or you can visit our web site www.brimrose.com and after that we can have additional discussions. | ||
| Michel Coene (Michel) |
Diode arrays are mostly build for use in telecom equipment (DWDM fiberoptic communication). Spectroscopy represents such a small market for the manufacturers that they are often not interested in developing arrays optimized to our specific needs. The last time I had a chance to compare AOTF/Diode Array, DA lost big time on the S/N comparison. You can increase S/N by averaging scans, but this again has its limits. When choosing a model/manufacturor however, make sure to ask yourself the right questions: -What do I want to measure? -WHERE do I want to measure it? (Is the lab really the best place? How about measuring it inside the truck/bag/mill...) -How accurate does it REALLY have to be? (Ask QC, and they will say 0.05% over the full range ;-)...) -How many samples per day? If there are a lot, you might want to look at software, unless you fancy writing down all the results by hand... -What comes next? (The Seedmeister eg, can sort the grains in a number of bags according to protein content. Is this usefull, or are you just after the statistics?) | ||
| john |
We currently use InGaAs diode array spectrometers in our lab for both Near-IR and for 1064nm Raman. I have a friend at ARO who is using the Brimrose AOTF for 1064 Raman also. The S/N requirements for Raman are much more demanding than any Near-IR applications we have encountered. In general, the diode arrray offers superior S/N Raman for similar acquisition times (0.5 seconds for polyimide). It is difficult for an AOTF to compete with the multiplex advantage of a diode array in terms of S/N. However, users that are unfamiliar with the way an array operates, often confuse pixel-to-pixel variation with random noise. Actually, this type of fixed-pattern noise is easily eliminated and most commercial diode-array spectrometers offer this. John Cooper Old Dominion University |