Unico 1200 Series User Manual

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5. Insert a test tube or an empty cuvette with cuvette holder, and blank the instrument.
If the energy is low, adjust the lamp by “pulling” or “pushing” it so that the light beam
is focused on the entrance slit of the monochromator. Since the lamp socket is pre-
aligned, there will be minimum, if any, adjustment required.
6. Tighten the lamp holding screws and re-install the access door.
Wavelength Calibration Check
Normally the UNICO
®
1200 Series spectrophotometer retains its wavelength calibration
indefinitely. However if the instrument receives a severe shock or is abused, use the
following methods to check wavelength calibration. Please note that this test requires
the UNICO
®
Didymium filter, item number S-90-9116, or the Holmium Oxide filter, item
number S-90-9115.
In the filter method, the didymium filter has two distinct absorbance peaks at 529 nm
and 807 nm. The Holmium filter has a distinct peak at 361 nm. When the instrument is
calibrated properly you will find minimum Transmittance (maximum Absorbance) at the
range ± 2 nm from these peaks. Note that the specific Transmittance values are not
important as you are only looking for the wavelength where the minimum Transmittance
(maximum Absorbance) occurs.
Note: If you calibration filter has a certified peak/valley curve attached, please use the
peaks on the curve to verify the instrument.

Unico 1200 Series Specifications

General

Brand	Unico
Model	1200 Series
Category	Measuring Instruments
Language	English