Merck Spectroquant Prove 300 - When to Repeat the Zero Adjustment; Measurements

Version 1.1 – 10/2015
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4 Operation – 4.4 Measurements
4.4 Measurements
The spectrophotometer can be used to perform the measurements listed below.
Type of Measurement Description
Concentration • Preprogrammed methods that can be executed using Spectroquant® test kits or self-prepared
reagents
• User-programmed methods
Absorption / transmission • Single-wavelength measurements for establishing the absorbance or transmission of solutions
• Multiple-wavelength measurements for establishing the absorbance or transmission of solutions
Spectrum • Programmedmethodsforestablishingtheabsorbanceortransmissionofsolutionsoverade󹭯ned
wavelength range
Kinetics • Programmedmethodsforestablishingtheabsorbanceortransmissionofsolutionsoverade󹭯ned
period
Quality checks Instrument-supported analytical quality assurance:
• Instrument check (AQA 1)
• Method-speci󹭯csystemcheck–preprogrammedforallSpectroquant®standards(AQA2)
• Pipette volume control (PipetteCheck)
• Check interferences from foreign substances (MatrixCheck)
4.3.2 When to repeat the zero adjustment?
We recommend that you repeat the zero adjustment in the
following cases:
• If the spectrophotometer was subject to mechanical stress
such as strong shock or transport
• If the ambient temperature has changed by more than 5 °C
since the last zero adjustment
• At least once a week. The interval to repeat a zero adjustment
is set in the instrument to 7 days. You can change this under
“System (Instrument Settings)"
• If a new cell type (different manufacturer, different glass type)
is used
• Basically, each time you want to measure with the highest
possible accuracy
NOTE
If an interval to repeat a zero adjustment is set you will be
prompted to repeat it after the interval has passed. You can also
repeat a zero adjustment by selecting a method, then touching
the “Settings" icon. Choose "Zero adjustment" and insert a zero
cell to start the measurement.