Foss NIRS DA1650, User Manual

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NIRS™ DA1650
User Manual 6008 1286 / Rev. 8 2:3
2.2 Principle of Operation
A sample, ground or unground, is placed in a sample cup which is placed in the
instrument. By means of a motor, the cup is turned so that multiple parts of the
sample is scanned. This multipoint reflectance measurement allows for an accurate
analysis of the sample. For inhomogeneous samples like pellets it is crucial with a
multipoint measurement.
Fig. 2:3Sample cup in instrument
2.3 Sample Cups
2.3.1 General
All sample cups used with NIRS DA1650 fulfill the requirements of ISO 12099
requiring a quartz window to eliminate drying effects of the interacting sample
surface layer.
Analysis can be done with a range of different sample cups. The most commonly
used are the Small cup and the Large cup. Other cup types are shown in section 2.3.3.
The small cup is intended for fine samples in granular or powder form and products
that are easy to compress. When placing the small cup in the sample presentation unit
the holder must be used. (The holder is shown between the sample cups in the
illustration below.)
The large cup is intended for unground or coarse samples like whole grains, pellets
or cut silage. The bottom and upper part of the Large sample cup are screwed
together and can be taken apart for e.g. cleaning or for replacing the glass if needed.
The bottom part also fit with the "Large cup extension".
Note: When filling the cup it is important that the bottom of the
sample cup is completely covered so that no light leaks through.
If you are not sure of which cup to use for your application, please contact your local
FOSS product specialist.