BUCHI NIRFlex N-500 - Manual (Page 60)

6 Operation
60 NIRFlex N-500 Operation Manual, Version F
6 .4 NIRFlex Solids
6 .4 .1 Reference measurement for the Petri dish add-on
A pop-up will remind the operator to measure the External Reference as soon as a certain time
window (predefined in the Application Designer) has passed.
A new External Reference is mandatory
when a new application is selected •
when an add-on or a new measuring cell is selected •
every time the software is restarted •
To measure the External Reference, proceed as follows:
Remove any sample from the add-on and ensure that the glass window is clean. •
Make sure that the bottom side of the External Reference and its holder is clean. •
Place the holder with the External Reference on the petri dish add-on and measure the External •
Reference.
6 .4 .2 Reference measurement for the XL add-on
A pop-up window will remind the operator to measure the External Reference as soon as a certain
time window (predefined in the Application Designer) has passed.
A new External Reference is mandatory
when a new application is selected, •
when an add-on or a new measuring cell is selected, or •
every time the software is restarted. •
To measure the External Reference, proceed as follows:
Remove any sample from the add-on and ensure that the sample glass window is clean. •
Make sure that the bottom side of the External Reference and is clean. •
Place the External Reference on the XL add-on, rotate it until the mark on the reference is next to •
the hole in the XL add-on, and measure the External Reference.
6 .5 NIRFlex Solids Transmittance
Diffuse transmission measurements are very demanding applications, because only a very small part
of the incident light is transmitted. Therefore care must be taken for good signal-to-noise ratio. The
design of the NIRFlex Solids Transmittance and its optimized detector ensure best performance.
NIRFlex Solids Transmittance uses a low energy source, which avoids any overheating of the samples
and therefore enables the analysis of temperature sensitive active ingredients. Emissions e.g. from
fluorescent tubes can cause artifacts in the sample spectrum. Therefore the cover of NIRFlex Solids
Transmittance must be closed during measurements.
NOTICE
Risk of incorrect measurement results by ambient light
Keep the top cover closed during a measurement •