BUCHI NIRFlex N-500 - Manual (Page 58)

6 Operation
58 NIRFlex N-500 Operation Manual, Version F
6 Operation
This section describes how to start a measurement and how to prepare a reference measurement and
gives recommendations on possible applications of the instrument.
NOTICE
Risk of instrument damage at use with engaged transportation lock.
Disengage the transportation lock prior use •
Keep shocks and vibrations away •
6 .1 General recommendations for measuring solids
The calibration wavelength range with a standard fiber optic probe goes from 4500 to 10000 cm -1 .
For quantitative applications the fiber optic probe should be fixed.
Hygroscopic samples show temperature dependency. The samples should either be measured at a
constant temperature or the temperature influences must be considered during calibration.
Coarse grained samples must be possibly milled before carrying out the measurement.
Number of scans: Qualitative calibration: 4−16 (max. 32); quantitative calibration: 16−32;
granules: 64. The spectral range of the NIRFlex Solids Transmittance is limited to 6000 cm
-1 . The
number of scans should be 64 by default.
General recommendations for measuring solids
Sampling option Substance External Reference measurement Comment
NIRFlex Fiber Optic Solids Homogenous powder
(qualitative) solids with
flat surface White standard in the
reference cap
NIRFlex Solids with petri dish
add-on Powder (quantitative)
granules White standard in a refer-
ence holder Make sure that there is
enough sample in the dish so
that all the light is reflected
by the sample
NIRFlex Solids with XL add-on Powder in containers
pellets
White standard on XL
add-on Make sure that there is a
constant bulk density, a
constant sample container
quality and a reproducible
container position
NIRFlex Solids with vial
add-on Powder in small glass
vials White standard in vial
add-on
NIRFlex Solids with Spinner
add-on Powder (quantitative),
granules White standard in a refer-
ence holder
NIRFlex Solids Transmittance tablets, capsules,
powders in small
plastic cups Open beam (reference
position in sample plate)