Offset Absorbance; Lamp Saver And Lamp Warmup - Awareness Technology Stat Fax 4200 Operator's Manual

2.4.5 Offset Absorbance

If Differential Filter is set to "None", then the Offset Absorbance field is displayed.
TEST DEFINITION
Name
Mode
Test Definition – Offset Absorbance field displayed
The user should determine the value of the Offset Absorbance. This value will be
subtracted from the absorbance readings to correct for the meniscus effect for the test that
is being run. Select the Offset Absorbance field and enter the user-determined offset
absorbance value. Press the Save button to save the settings.
Offset Absorbance feature is only needed when both of these conditions occur:
Monochromatic reading

No blank well

It is a mathematical blank to correct for the differential between air and liquid with a
meniscus.
To determine the user-entered value, pipette a volume of wash buffer into a well that is
equal to the total volume in test wells at the read time.
For example, if the well has 100µl of Substrate Part A per 100µl of Substrate Part B, plus
50µl of stop solution, the total volume in the test wells at the read time is 250µl. Therefore
read the absorbance of 250µl of colorless wash buffer to determine the correct value for
the Offset Absorbance. Typical values are from .250 to .400A.

2.4.6 Lamp Saver and Lamp Warmup

After a period of inactivity, there is a lamp time-out feature that will automatically turn off
the lamp. The default setting is 600 seconds (10 minutes). This can be adjusted using the
Lamp Control feature located in Settings. The range is 30 to 3600 seconds.
Lamp Warmup has a default setting of 45 seconds. This can also be adjusted from the
Lamp Control feature. The range is 45 to 240 seconds
Stat Fax ®
Absorbance
Primary Filter 405
Differential Filter 630
Blank NO
Offset Absorbance
Print Save Run
4200 Operator's Manual Doc. 4200 Rev. K
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