Temperature control
193
Goldeye G/CL Technical Manual V4.1.1
After powering up the camera, at first the camera temperature rises. This is due to
heat generation inside the camera, and possibly caused by warm ambient
temperature. To keep the sensor temperature constant, the TEC keeps it at a
predefined temperature setpoint (see
).
The TEC keeps the sensor temperature as long as the difference between sensor
temperature and case temperature does not exceed the predefined
Δ
T ( see
).
If the case temperature keeps rising, the difference between sensor- and case
temperature exceeds the predefined
Δ
T. T
he temperature control is no longer able
to keep the sensor temperature at the current setpoint. The TEC switches up to the
next higher setpoint. The existing NUC data, that is optimized for the default
setpoint conditions, is still applied at other setpoints.
Switching to the lower setpoint
When the ambient temperature decreases, this causes the temperature of the
camera to decrease as well. With further temperature decrease, the sensor
temperature can fall below the current setpoint temperature. The TEC might be no
longer required to cool the sensor to the adjusted temperature setpoint. If the
sensor temperature no longer depends on the the TEC cooling only, it becomes
unstable.
To avoid temperature instability, the TEC switches down to the next setpoint,
before the cooling power is reduced to the critical range at the current sensor
temperature.
To keep the current sensor temperature as long as possible, the TEC does not
switch down immediately when the min.
Δ
T to the next temperature setpoint is
reached. These points are marked in green in Figure 62.
Figure 62: Schematic figure of setpoint switching downwards (Note for better
understanding the case temperature profile is shown in a simplified way that
covers the whole temperature range.)
0
10
20
30
40
50
60
Temper
atur
e in
°C
Time
Case temperature
Sensor temperature
Setpoint 1
Setpoint 2 (Default)
Setpoint 3
Setpoint 4
Min.
ȴ
T reached
Min.
ȴ
T reached
