Stat Fax 303 Plus, Operator'S Manual

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Awareness Technology, Inc. Stat Fax 303 Plus Operator’s Manual Rev. J 35
“Off Curve” is printed when a sample value is greater than the highest calibrator or less than
the lowest calibrator.
“PRINTER JAM” is displayed when the internal printer paper path is obstructed. It must be
cleared before printing can resume. To avoid this problem, never feed paper backwards, and
never load paper with a rough cut edge.
“Mechanism Error” and “TEST ENDED” are both displayed and printed when the strip can not
be transported properly. This usually indicates improper strip loading, obstruction, or a
mechanical failure. Use only standard size microstrips and microwells, and ensure they are
seated firmly in the carrier.
“Lamp/filter(s) low!” is printed when less light than necessary is detected, which may indicate
that the lamp's light is low or that the light through a specific filter is low. You will be given the
option to continue to read, but this message may indicate decreased linearity. You may require
lamp replacement or filter replacement. Call your dealer for service assistance if needed.
“Reposition Carrier” is printed if you attempt to use a carrier position other than the right-most
for your first strip in a mode. Reposition the carrier to the right-most position and re-run.
“ No Carrier” is printed if you press Enter to read when no carrier is loaded.
“MEMORY IS FULL” is displayed if you attempt to store more tests than are available.
“DO ABS SET TEST 212!” is printed when the factory set absorbance gain calibration has been
lost from non-volatile memory. Instructions are located in Section 3.1, Restoring Electronic
Calibration.
2.4.4 Differential Absorbances
This instrument requires the selection of two filters: the operating filter and a differential filter.
Use of the bichromatic differential absorbance increases precision, since the element of variation
that is caused by imperfections in plastic microtiter strips is removed from the results.
In order to preserve the sensitivity, however, it is important not to choose a differential filter
where the chromophore being assayed exhibits substantial absorbance. A monochromatic
option is available for use in scanning the filters independently. To look at only 1 filter, select 0
as the differential filter.
When reading monochromatically, the blank absorbance is elevated relative to the curvature of
the meniscus. A correction, called “offset absorbance”, can be entered by the user to
compensate for this effect.
To determine the correct offset absorbance, read a well of your blank material in the absorbance
mode, monochromatically without blank or offset. Determine the difference between the
observed and expected value. This is your offset absorbance.
When no differential filter is selected, the message “OFFSET ABS Y/N” is displayed. If you
answer YES, you see “OFFSET ABS =” . Enter the value that should be subtracted from the
observed blank absorbance.