| Author | Message | ||
     Hendra Herdian (hendravit) Junior Member Username: hendravit Post Number: 6 Registered: 2-2007 |
Dear all, thank for all the sugestion, they all great. it's helpfull for me to increase my knowlege especialy on NIR for Feed. Once Again Many thank. Hendra | ||
| Bruce H. Campbell (campclan) Moderator Username: campclan Post Number: 105 Registered: 4-2001 |
I want to add what Tony nicely said about the use of English. If a questioner has no other source of information that would enable the problem to be discussed, what better place than this group? Even if another source is available, the more responses the better. If a question is difficult to understand, a request for a different wording is easily sent. Further, the problem may be such that putting it into words is difficult; that is, the questioner may not have experience or knowledge to phrase the question with great clarity. ( A note here: if a problem is understood with great clarity, it is well on the way to being solved.) I could put down more reasons for the questions not being well written. However, this forum is for everybody. If we stop having perfectly clear questions, most of us with less than perfect English skills would be prevented from using this forum. Bruce Campbell | ||
| Dennis Karl (dennisk) Junior Member Username: dennisk Post Number: 10 Registered: 4-2004 |
Dear Hendra, I completely agree with Tony and others about the reliability of determining 'ash' in feeds. Our laboratory is in the feed milling business and have been analysing compounded stock feeds for the last 12 years by NIR. We have found that determining 'ash' is completely unreliable, and totally inacurate, for all feed types which contain added minerals. these feeds include poultry broiler and layer feeds, pig feeds and the like which have significant levels of added minerals in the form of limestone and di calcium phosphate. NIR does not pick up any of the added mineral materials. The minerals do cause a baseline shift which some claim to be able to be exploite to measure ash but...... ?? We do have a limited amount of success with feeds which do not have added minerals, and with forages. These tend to be the feeds intended for ruminant animals which have little by way of added minerals so the ash error is not as pronounced. I hope this helps Dennis Karl | ||
| Tony Davies (td) Moderator Username: td Post Number: 164 Registered: 1-2001 |
Dear Hendra, Just a comment about ash. It may be possible to make a calibration for ash and it may validate against a test set. But using the results is very dangerous because ash (in general) does not absorb NIR energy and the calibration will be based on correlations between ash and some other component or components which do absorb NIR. If you have a sample with unusually low or high ash it is very likely that the calibration would not see it. Your answer would be wrong just when you need it to be correct so NIR analysis of ash should NOT be used. Please do not believe what others may tell you! Good luck! Best wishes, Tony PS There is a quote from Karl Norris recorded by Peter Griffiths in JNIRS 4, 21 (1996). "This guy can't tell his ash from a hole in the ground"! | ||
| Tony Davies (td) Moderator Username: td Post Number: 163 Registered: 1-2001 |
Dear Gabi, I disagree with you most strongly in your comments about the standard of English. I suggest you consider the following: 1) The questioner may have no colleagues who understand what NIR analysis is about. So even someone with English as a first language would not be much use. 2) Answering queries is entirely optional. Best wishes, Tony | ||
| David von Boisman (david_von_boisman) New member Username: david_von_boisman Post Number: 5 Registered: 2-2006 |
Dear Hendra, Generally speaking, the Infratec 1255 is a very old design and we (I work for FOSS at the former Tecator headquarters) have not promoted it for feed for the last 10 years as there is much better instruments available today. Nevertheless it should be possible to determine the basic stuff such as protein, fat & moisture, again, if the sample is well prepared. Ash/minerals may be tricky. Send me an e-mail at [email protected] for more info. | ||
| venkatarman (venkynir) Senior Member Username: venkynir Post Number: 48 Registered: 3-2004 |
Dear all; I will support Mr.Garvriel Levin , he is correct in his words. You are all aware that the application of NIRS is growing spontaneously with different sensing methods . Questionnaires should be specific and clear. There should not and any ambiguity and should not be a open domain in the question . It helps us think and reply to user. | ||
| Hendra Herdian (hendravit) New member Username: hendravit Post Number: 5 Registered: 2-2007 |
first i do appoligize about my english phrasing from my last posting that can confuse every one in this forum, i realy sory. i'll try to improve better in the future. Gabi is right, im looking for determination of fat, protein etc, since my equipment(infratec 1255) is only operate on 700-1100 nm, i like to know the equipment performans on that region specialy for feed analyzing. | ||
| David von Boisman (david_von_boisman) New member Username: david_von_boisman Post Number: 4 Registered: 2-2006 |
Hi Hendra What kind of instrument do you have? To get good results in that wavelength region you need to work in transmission - which is difficult but not impossible in feed - as you need to get down to a pathlength of 2-3 mm to make it work, where sample preparation and kuvette design are chritical factors. | ||
| Gavriel Levin (levin) Senior Member Username: levin Post Number: 53 Registered: 1-2006 |
Hi everyone I have wished to point this before - I think that we should ask people who seek advice from the forum to take some time and polish the English they use - we spend our time to provide answers, and most of us do so with a high level of proper and mistake free language. Sometimes the phrasing is such that we waste time just trying to figure out what is the question. I understand that he is looking for determination of fat, protein, ash, etc. but in what products? grain? what grains? corn? wheat? etc?. The region 700 - 1100 is a good region for diode arrays because you could use silicon arrays with large number of pixells (512 or 1024), so the resolution is quite good, helping to improve the situation which is not favorable due to the high "packing" of the spectral information into a narrow region (actually less that 400 nm). Many of these parameters have been determined by analyzers operating in this region with decent success in products such as grains. Gabi Levin | ||
| Hendra Herdian (hendravit) New member Username: hendravit Post Number: 4 Registered: 2-2007 |
dear all, what feedstuff materials (i.e. protein, fat,etc) constituen which cleary identified by the NIR 700-1100 nm spectral absorption, can we do determined the ash/mineral feedstuff content using the same region thank you |