BUCHI NIRFlex N-500 - Manual (Page 59)

6 Operation
59 NIRFlex N-500 Operation Manual, Version F
6 .2 General recommendations for measuring liquids
For sample measurements with the NIRFlex Liquids, make sure that the cuvettes are placed in the
direction of the centre of the cuvette holder. This is important to ensure optimal heat transfer to the
sample.
The calibration wavelength range with glass cuvettes goes from 4000 to 10000 cm
-1 .
The useable wavelength range for measurements with a fiber optic probe is 4500 – 10000 cm -1 .
Temperature differences can cause a spectral shift. The samples should either be measured at a
constant temperature or the temperature influences must be considered during calibration.
Avoid air bubbles.
Number of scans: Qualitative calibration: 4−10; quantitative calibration: 16−32 (max 64)
General recommendation for measuring liquids
Sampling option Substance External Reference measurement Comment
NIRFlex Liquids Transparent liquids Built-in External Reference
(air) 1, 2, 5, 10 mm
cuvette with spacer
NIRFlex Fiber Optic Liquids Transparent liquids
aggressive, trans-
parent liquids
Clean probe head Max. temperature
150 °C
avoid air bubbles
NIRFlex Solids with petri dish
add-on and transflectance cover Clear liquids, turbid
liquids Empty petri dish with
transflectance cover Avoid air bubbles
NIRFlex Solids with flow-cell
adapter add-on Clear liquids, turbid
liquids Clean flow cell Avoid air bubbles
NIRFlex Solids with Spinner add-on
and transflectance cover Clear liquids, turbid
liquids Empty cuvette with trans-
flectance cover Avoid air bubbles
NIRFlex Fiber Optic Solids with
transflectance adapter Clear liquids, turbid
liquids Clean probe head Make sure there
are no air bubbles
in the gap
6 .3 Starting a measurement
The spectrometer needs a warm-up time of approx. 15 min. The lamp and the laser within the instru-
ment will be switched on as soon as the NIRWare software is running.
When the instrument has warmed up and the sample is presented to the instrument, you can start the
measurement.
Generally, you have two possibilities to do so:
Press the START button at the measuring cell. 1.
Click the Start icon (green arrow) in the NIRWare Operator. 2.
NOTE
When you are working with the NIRFlex Fiber Optic Solids or NIRFlex Fiber Optic Liquids probe, you
can also use the remote button on the handle to start a measurement.