| Author | Message | ||
     Sarah Smyth |
Working with a UV-VIS-NIR 570 integrating sphere, we have encountered the following problems- using ceramic samples including various lustres and glazes- we at first found reproduction of results diffilult- hence the decision to create a window (with black card) to contain the different colours of glazes and lustres. We did not however take into account the covering of the PTFE white tile with the same window- our results showed consistant problems with intensity (less than -o.8 max)How & why may this account for our problem? | ||
| Tony Davies (Td) |
Hello Sarah, I think I need some more detail. I do not yet understand what you are trying to do. Is this a new or old instrument - I do not recognise the number. Can you give the sample size, the size of the window in the integrating sphere,the size of the standard and the optical arrangement of the instrument? What is your measurement of intensity? Best wishes, Tony Davies | ||
| Art Springsteen |
It sounds to me like you have a combination of two problems- a set back effect and translucent blurring effect. As PTFE is a bulk reflector, any set back from the port will cause a lowering of reflectance (rule of thumb is about 4% loss per mm. set back). Translucent blurring effect describes the problem when some of the reflected radiation is lost behind the mask. You need to greatly underfill the sample with a bulk reflector or this problem will occur. This is not a problem with tiles or ceramics, which are largely surface reflectors. You've got me puzzled, too. What is a UV-Vis-NIR 570 integrating sphere? Best regards, Art Springsteen, Avian Technologies LLC | ||
| Sarah Smyth |
Firstly thanks for the responses, the model ILN-472 is a large integrating sphere attachment (to accompany V-570 UV-VIS-NIR)designed to measure the transmittance and reflectance of a sample which diffuses light. Normally when a sample is measured, the light incident upon the sample is diffused and only a small portion of the light reaches the detector giving an inaccurate result-this attachment acquires most of the light diffuse transmitted or diffuse-reflectance at the sample into the integrating sphere and introduces it into the detector, permitting accurate measurement. The inside diameter of integrating sphere is 150mm, sample sizes max:3x3cm, window size 5x5mm. Our objective is to measure the absorbance/reflectance of glazed and lustred ceramics one colour at a time to see the relationship of bands appropriate to the components of the relative glaze/lustre (the window size is proportional to the size of any given part of the ceramic covered with diverse glazes-observed by their different colours to exclude interference from other coloured components.) Kind regards |