Metachrome Ii; Certificate Of Calibration; Window; Ccd Chamber - Photometrics SenSys User Manual

®
Metachrome II is a proprietary, optional, permanent CCD coating that is
Metachrome II
available on all SenSys CCDs. This coating extends the CCD's sensitivity to
below 200 nm and is transparent from 400 to 1100 nm wavelength light. The
coating requires no maintenance and does not degrade over time.
Certificate of Calibration Each SenSys camera has a Certificate of Calibration. This certificate states the
CCD grade that has been designated by the CCD manufacturer. The certificate
also provides the camera calibration information needed to effectively measure
photon flux with repeatable, scientific accuracy. A copy of the information
contained in the Calibration Certificate is kept on file at Photometrics Customer
Service.

Window

The SenSys camera has one window in the optical path. The CCD does not have
a window. Compared to a multiple-window design, a single window reduces
the chance of image degradation due to multiple reflections, stray light, and
interference patterns.
The standard Photometrics window is made of fused silica (quartz) with a
broadband antireflective coating. Fused silica has better ultraviolet
transmission than crown glass. The antireflective coating increases the light
transmitted through the window from 92% to 99%, further decreasing light loss.
Optional infrared-blocking (IR) and sapphire windows are available. The IR
window blocks optical radiation above 650 nm, providing a sharper image. The
sapphire window may be necessary for high-humidity environments.

CCD Chamber

The window is part of the sealed chamber that protects the CCD from
contamination and excess ambient humidity. Inside the sealed chamber,
packages of desiccant absorb any water vapor.
When the camera is cooled to 10°C, the low-humidity environment prevents
frost from forming on the CCD and condensation from forming on the inside of
the window.
Thermoelectric
Cooled CCD cameras produce less dark current than cameras operating at
Cooler
ambient temperature. The CCD in the SenSys camera is cooled to 10°C when the
ambient temperature is between 10°C and 40°C.
The CCD is cooled by a single-stage Peltier cooler, a thermoelectric cooler (TEC)
that pulls heat away from the CCD. The heat is rejected into the camera body,
which is cooled by forced air.

Shutter

The camera has a high-speed, customer-replaceable shutter that maintains a
speed of up to 15 frames per second while still fully opening and closing. The
shutter takes 5 ms to open and 10 ms to close. The camera integration time (the
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SenSys User Manual