Bio-Rad iMark Microplate Absorbance Reader - Manual (Page 14)

iMark Microplate Absorbance Reader Instruction Manual
8
Instrument Functions
Calculations
The Microplate Reader uses Beer's Law to calculate the absorbance value of each well. Beer's Law states that
absorbance is equal to the log10 of the ratio of the baseline measurement intensity (Io) to the sample
measurement intensity (I).
Beer's Law: Absorbance = Log10 (Io/I)
Before measuring the plate, the reader takes a reading for all eight photodiode channels. These values are
recorded as the baseline measurement (Io) values for each channel, respectively. The reader then records the
sample measurement (I) value for each well, and calculates the absorbance using these values.
Channel-to-channel error is significantly reduced because the Io value for a given channel is used only in
determining the absorbance of the wells of that channel.
Security password
The iMark Microplate Reader requires a user login with password. This security feature helps to prevent any
unwarranted modifications to the analysis conditions/protocols and data stored in the instrument, and identifies
the operator on reports. The reader has two user settings, the Administrator and the Common user. Each user level
has its own security password.
Memory Back-Up
The battery back-up provides memory even after the reader is turned off.
The following information will be saved in the memory until new reading parameters are set by the user or a new
plate is read by the instrument. Note that if a run is aborted before it is finished, all the previous plate reading data
remain in memory and none of the data from the aborted reading is stored.
• The ten latest sets of End-point protocol plate reading results
• The two latest sets of Kinetic plate reading results (max. 30 series of readings for each Kinetic
Protocol)
• 64 End-point Protocol settings and 2 Kinetic Protocol settings
• A set of Checkmark reference data and the one latest set of Checkmark reading result
• A set of standard curve data for the storage of standard curves and graphs
• Eight wavelength values for filters
• Laboratory name
• Two security passwords (for the Administrator and the Common user)
• Instrument serial number
In addition to the battery back-up memory, the instrument has a small amount of non-volatile memory to keep the
system information after the battery is dead. The serial number is stored in this memory. The average battery life
is 5 years.