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Piranha 2 User’s Manual
03-032-00493-14
Teledyne DALSA
4
Optical, Mechanical, and
Thermal Considerations
4.1 Mechanical Interface
The camera’s electronics are housed in a rugged ized lightweight aluminum case.
Mounting
The cam era can be m ou nted u sing the M3 holes (m etric-thread ed ) on its base or top , and
on its front p late at the corners.
Environment
The cam era an d cables shou ld be shield ed from environm ental noise sou rces fo r best
op eration. The cam era shou ld also be kep t as cool as p ossible. The sp ecified op erating
tem p eratu re is 10–50°C m easu red at the front p late, (the corresp on d ing am bient
tem p eratu re range w ith still air is 0°C to 37°C). Mou nting holes (refer above) allow you to
attach heat sinking.
Thermal Management
For any CCD cam era op tim al p erform ance is achieved by transferring heat aw ay from the
sensor. Keeping a sensor ―cool‖ reduces the amount of d ark current generated. Dark
cu rrent is the lead ing contribu tor to FPN , PRN U, d ark offset, rand om noise and other
p erform ance sp ecifications, esp ecially w hen a cam era is significantly gained (i.e. +10d b).
Generally, d ark cu rrent d ou bles for every 7°C increase in tem p erat u re at the sensor an d
increases linearly w ith integration tim e. Fu rther variation s in d ark cu rrent can not be
com p en sated for w ith ou r flat-field correction algorithm s. For this reason, at high gain s
(+10d B), high tem p eratu res (40°C front p late), and low lin e rates, it is recom m end ed that
you recalibrate the flat-field coefficients w hen the tem p eratu re shifts by ±10°C.
N ote:
Up on initial p ow er-u p the front p late cam era tem p eratu re is near am bient. It is
recom m end ed to p erform flat-field correction once the cam era gets w ithin 10°C of its
stead y state tem p eratu re. For Piranha 2, at an am bient tem p eratu re of 25°C and w ith no
airflow , the cam era takes 90 m inu tes to achieve stead y state and 20 m inu tes to reach
w ithin 10°C of stead y state. If you r system cannot p erform flat-field correction after
w arm -u p consid er the recom m end ed m ethod s of red u cin g d ark cu rrent and overall
cam era tem p eratu res (see below ).
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