68 PI-MAX/PI-MAX2 System Manual Version 5.F
Number of Images/Spectra and Accumulations
This is the number of sequential frames the software will collect and store in a single file.
Each frame will be digitized and stored, but all of the frames will be in a single file. A frame
may contain data from more than one region of interest as defined via the ROI Setup tab.
If the Accumulations > 1, each stored frame will contain summed data sets from two
or more exposures. The number of separate frames stored will the same as it would be for
Accumulations =1, but the total number of exposures required would be the product of
the Number of Images/Spectra parameter times the Accumulations value.
CCD Readout
This parameter selection determines whether the entire CCD array will be used to acquire
a frame or if only a rectangular portion (or portions) of the array will be used. When Use
Region of Interest is selected, data will be collected from the region(s) defined on ROI
Setup tab. The full chip size or the sum of the active region(s) as defined on the ROI tab
is displayed.
Amplifier
If the CCD is a Thomson 512 × 512 CCD array, either the high-capacity (fast) or the low-
noise array output node can be selected. The actual selection is made by selecting FAST
(high capacity) or SLOW (low noise) on the Experiment Setup|A/D tab. The parameter
indications High Capacity and Low Noise on the Experiment Setup|Main tab are
reported values only. The default setting is read from non-volatile RAM (NVRAM) in the
PI-MAX. If the selection is changed, the new setting is written to the NVRAM and
becomes the new starting default.
High Capacity: Allows the camera to collect 16-bit images at a readout rate of
up to 1 million pixels per second.
Low Noise: When operating at a lower speed, the camera provides superior
noise performance.
Intensifier Gain
The Intensifier gain provides continuous adjustment over an arbitrary range of 0-to-255.
The default setting of 128 will give good results in many applications. Once the ST-133
is turned on, the gain can be adjusted any time during image acquisition. We suggest
beginning with a low setting and then increasing it until optimum results are obtained.
Note: The intensifier gain also affects the dark charge of the intensifier (EBI). One result
of this is that, to properly perform background subtraction, a new background must be
taken whenever the intensifier gain is changed.
Intensifier Mode
The Intensifier Mode selection determines whether the intensifier will act as a mechanical
shutter that is biased on or off based on the set exposure time (Shutter Mode), it will be
biased on or off by the defined pulser gate timing (Gate Mode), or it will be continuously
biased off until either Shutter mode or Gate mode is selected (Safe Mode).
To Next Page
Loading...
