| Author | Message | ||
     darren |
G'day I am currently working on a project looking at the future application of portable NIR technology in horticulture. I am interested in speaking to anyone with experience in using such technology. I am not a researcher of NIR, instead I am coming from an extension perspective. Many Thanks Darren | ||
| W. Fred McClure (Mcclure) |
Darren, I have done considerable work on the optical properties of horticultral products. Perhaps I can share some publication with you if you wish. You may contact me directly: [email protected] Fred | ||
| M. Coene |
Does anbody have experience in transferring applications from "real" spectrometers to these small portable ones? I am not looking for specific applications but I wonder how well these things perform nowadays. | ||
| Todd Rosenthal |
I know commerial posts are not allowed, but DArren's email link did not work. Please check www.zeltex.com website for portable NIR analyzers. To: M. Coene. All work I have done trying to transfer from "real" spectrometers to portables has had very limited success. | ||
| nidhi |
hi daren , contact me, i'll give you a contact | ||
| hlmark |
In fairness, then, I think we should at least list other companies making similarly small (or hand-held) instruments (in alphabetical order): Brimrose Infrared Fiber Systems Ocean Optics \o/ /_\ | ||
| Darren Morrow (Darren) |
Thankyou for your help Darren | ||
| G |
Hi, I am sorry I am late to respond, I was doing heavy travel. Horticulture is a wide subject. I have done some work, but to be able to be useful, please specify the application, if you may. Not to be commercial, I will appreciate direct contact to explore the issue of quality when downsizing the hardware either by providing e-mail for direct communication or by phone to 410 931 7200 and if I am not there, leave a message with either Robert, Danny or Diane. Thanks, Gabi Levin | ||
| Alan Green (Alan) |
Moisture Measurement Wavelengths I am looking at attempting a portable NIR instrument to measure moisture content using reflectance of the light. I gather the best choice for absorption is 1940 nm but what is the prefered reference wavelength if I go with the differential approach? Any suggestions are most appreciated. | ||
| Bruce H. Campbell (Campclan) |
Alan, I assume you mean you want to build such and instrument. Are you looking at using one and only one wavelength? You may not always have the best of accuracy if you use only one wavelength. If you are constrained to using only one, however, I would suggest a slightly lower one as water has a number of bands in that area; but since they are so close together, only one envelope shows when doing a scan of pure water. There is one wavelength section you may want to avoid. That section is at slightly longer wavelengths and is due to water of solvation, usually of ionic materials. Bruce | ||
| W. Fred McClure (Mcclure) |
Alan, You are talking my language. If you contact me directly, I will share our work on hand-held devices with you. My address is: [email protected] | ||
| Gabi |
I have read some of the follow up messages, and once again, would like to suggest one thing - using 1940 only with one wavelenght for differential is a way to perform in siutations where moisture only is subject to change. If as in natural products, other composition elements change as well, the differnetial is frequently insufficieint to guard against errors. Since today there are more than one full wavelenght range portable spectrometers, where is the advantage in one or two wavelngths. If you stay with one, consider that the longer wavelength will penetrate to a lesser depth than the shorter wavelength, thus, if the product you look at has a "skin" of significant thickness, with the longer wavelnghts you will possibly jeopardize your measurement. Not knowing enough about the application, being of any real use is difficult. Gabi | ||
| Alan Green (Alan) |
Thanks for the comments everybody. I didn't mention I was looking at a differential measurement setup which I should have. What I was wanting to be certain about was the 'best' wavelength for moisture measurements. I gathered that 1940nm was the choice after looking at specs from various instrument manufacturers and just wanted to check that was so before selecting the filters for a dual PbS detector. My work to date has been with rapid response hygrometers (>10Hz frequency response) that use path averaged absorption at 2.7 micron rather than reflectance techniques. The 1940 nm wavelength requires a rather long transmission pathlength to get sufficient S/N and this compromises spatial resolution for the type of environmental work I have been engaged in previously but this reflectance approach is different again. |