Andor Technology iXon Ultra 897 User Manual page 61

Tagged (or Tag) Image File Format (TIFF, .tif) is used for storing bitmapped images
and is widely supported by commercial publishing packages. When you save data as
a .tif file, the system automatically creates a file containing a number of labels (tags),
which describe key properties of the data (gray levels, byte format, etc.) As with
BMP, the image is exported WYSIWYG fashion.
The 'Export Raw Data' Dialog Box allows the user to save the active data set to a
.dat file located on disk. The .dat file comprises data only and has no header
information of any kind. The original data set remains unchanged.
A 'data set' refers to a collection of data comprising one or more of the following
subsets, selectable from the Export as .dat Dialog box
Signal (sig)
Background (bg)
Reference (ref)
Cal (Lamp Calibration)
A .dat file, however, will contain only one of the above data subsets. (Please note
that the cal subset is used in radiometry/colorimetry measurements. It does not refer
to the x-axis calibration of sig, bg or ref data.
The .dat file format
The .dat file format reflects the CCD sensor format, e.g., with a CCD sensor of 1024
columns * 256 rows then the first 1024 data values in the .dat file correspond to the
first row of the CCD, the second 1024 data values correspond to the second row, etc.
The .dat data type
Data Type No. of Bytes
16 bit integer
1) 2
2) 32 bit integer 4
3) 32 bit float 4
Option saves a data set to a 16 bit integer .dat file. Note: if a data value exceeds
1)
the limits of a 16 bit integer (<-32,768 or > 32,767), that data value is truncated to
the corresponding limit (e.g. if a data value is 36,000 then the value is truncated to
32,767).
Range
-32,768 to 32,767
-2,147,483,648 to 2,147,483,647
-38
3.4 x 10 to 3.4 x 10
DATA ACQUISITION
+38
Section 4 . 4
Page 61
TIFF
Raw Data