Metrohm NIRS XDS MultiVial Analyzer - Manual (Page 73)

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NOTE: The response of the WSR Wavelength Standard may vary slightly with temperature. This is
typically in the range a few hundredths of a nanometer for small temperature variations. While
this effect is small, it may cause some variation when running Wavelength Certification.
We suggest that the WSR standard be stored in the standards box, rather than inside the
instrument. When running a test with the WSR, place it in the instrument as directed, then take it
out and store it in the box, to keep the temperature as consistent as possible. Temperature inside
the instrument may be as much as ten degrees (F) higher, and may cause slight wavelength drift,
enough to cause slight wavelength errors when measuring wavelength response.
7.1.5 IPV Setup (Instrument Performance Verification)
IPV Setup is provided as a method to record initial instrument response to calibrated photometric
reflectance standards. This is normally performed upon initial installation, immediately after
Instrument Performance Certification (IPC), when a lamp has been changed, or when standards have
been re-certified.
When the standards are scanned during IPV Setup, a file is generated, and is stored in the Vision
directory. This file has the same format as the standards file, but a “V” is placed into the fourth
character of the file name. This indicates that it is a “verification” file. For example, if the standards
set has the serial number RSS10301, the IPV Setup file is named RSSV10301.
With the IPV Setup file stored, the user can run Photometric Test to check the repeatability of
instrument performance. This is detailed later in this manual, in “Evaluation Diagnostics.” Photometric
Test compares the current performance of the instrument to the file stored during IPV Setup, and
reports differences. If the instrument differences exceed established tolerance limits, the test reports
that, so corrective action may be initiated.
It is important that IPV Setup, and later Photometric Test, both be run with the same options selected
under Configure, Options. That is, if the IPV Setup file is acquired with Reference Standardization
switched on, and with Window Correction switched off, then Photometric Test should be performed
using the same settings. The System Manager should pay particular attention to this. If options are
not consistently applied, there will be a bias in the results of Photometric Test. The bias may be
enough to cause test failure, depending upon selections.
Because the XDS is a sensitive instrument, it can detect differences in temperature of the standards,
and results may be affected slightly. To minimize this effect, be sure the standards are at a stable
temperature before use. If lab temperatures vary, the user may place the standards inside the RCA
cover for some time to let them equilibrate to a stable temperature.
IPV Setup is run as follows:
Select IPV Setup from the Diagnostics menu.