Princeton 4411-0139 Home Security System User Manual


 
66 PI-MAX
®
4 System Manual Issue 4
Figure 5-3: WinX: Phosphor Decay Delay
Figure 5-4: LightField: Phosphor Decay Delay Parameters
5.5 Temperature Control
WARNING!
Under normal conditions, the front end of the camera is sealed and
backfilled so there is no danger of damage due to condensation.
5.5.1 Cooling Method
Cooling the CCD array reduces the amount of dark charge, thereby acting to improve the
signal-to-noise ratio. An internal Peltier device directly cools the cold finger on which the
CCD is mounted. The heat produced by the Peltier device is then removed by the air drawn
into the camera by the internal fans and exhausted through the side-panel grill. The fans are
always running and cooling the CCD and the internal electronics. Additional heat removal
can be performed by circulating coolant through an internal heat block.
Air-cooling
With air-cooling alone, at an ambient temperature of 25C, temperature lock at -25
should typically take ten to twenty minutes. Cooling performance is affected by the
CCD array being used (i.e., larger arrays may take longer to cool than smaller
arrays.) Also, if the lab is particularly warm, achieving temperature lock might take
longer or not be obtainable at all.
Supplemental Circulating Coolant
4411-0137_0023
ENTER PHOSPHOR
DECAY DELAY TIME
4411-0137_0024