Princeton 4300 User Manual

46 

PI-SCX System Manual 

Version 2.E 

 

46 

It is recommended that the camera warm-up be carefully controlled. Proper warm-up will 

be achieved by proceeding as follows: 

1.  While running WinView, gradually bring the camera temperature up in 10°C 

steps from its current lock temperature to ambient temperature. To accomplish 

this, open the 

 dialog, set the target temperature to 10°C 

above the current lock temperature, wait until lock is reached, and then raise it 

again in 10°C steps until ambient temperature is reached.  

2.  Set the ST-133 Controller’s front-panel Power switch to OFF. 
3.  Set the circulator’s refrigeration On/Off switch to OFF. 
4.  Set the circulator’s main power switch to OFF. This completes the warm-up 

procedure.    

The following topics address factors that can affect the signal acquired on the CCD array. 

These factors include array architecture, exposure time, CCD temperature, dark charge, 

and saturation. 

Charge coupled devices (CCDs) can be roughly thought of as a two-dimensional grid of 

individual photodiodes (called pixels), each connected to its own charge storage “well.” 

Each pixel senses the intensity of light falling on its collection area, and stores a 

proportional amount of charge in its associated “well.” Once charge accumulates for the 

specified exposure time (set in the software), the pixels are read out serially.  
CCDs are rugged and compact: unintensified, uncoated CCDs can withstand direct 

exposure to relatively high light levels, magnetic fields and RF radiation. They are easily 

cooled and can be precisely thermostated to within a few tens of millidegrees. 
Because CCD arrays, like film and other media, are always sensitive to light, light must 

not be allowed to fall on the array during readout (with a few exceptions). Unintensified 

full-frame CCD cameras like the PI-SCX cameras may require a customer-provided 

X-ray shutter to prevent light from reaching the CCD during readout.