Safety Features - Newport 6100 User Manual

System Operation
Constant Temperature Mode (Const Temp)
This mode holds the TEC at a constant temperature based on feedback from
the sensor in the TEC mount. In this mode, the 6100 uses a control loop
comparing the sensor input to the temperature set point (Ts), driving the Ite
current positive or negative to reach and maintain that set point. The
thermistor sensor's input is converted to temperature for display of actual
TEC temperature using Steinhart-Hart (S-H) equation. The RTD sensor's
input is converted to temperature for display of actual TEC temperature using
Callendar – van Dusen (C-vD) equation.
The sensor constants (both S-H and C-vD coefficients) can be modified using
"TEC:CONST" command or through the front panel.
Constant Resistance/Reference Mode (Const R)
This mode operates identically to the Const Temp mode, but the sensor input
is not converted to temperature; it is displayed in unconverted form.
Likewise, the set point is used directly, not converted from temperature.
Thermistor and RTD sensors use resistance ("Rs=" and "R=" variables),
LM335 sensors use millivolts ("vs=" and "v=" variables), and AD590 sensors
use microamps ("is=" and "i=" variables). Const R is primarily intended for
users who know a sensor set point in "sensor" units, not in ºC.
Constant Current Mode (Const Ite)
Unlike the modes above, the Const Current mode allows the operator to
explicitly set the amount and direction of current flow through the TEC, using
"Is=" and "Ite=" variables. If a sensor has been selected, the TEC
temperature will be displayed. Although temperature is not a factor in the
amount or direction of current flow, the high and low temperature limits are
observed, and will shutdown the output if exceeded in Const Ite mode, if a
sensor is selected. For no temperature limits, set the sensor type to "None."
Use caution when limits are not active, as the temperature may exceed your
TEC's thermal limits.
4.2

Safety Features

The Model 6100 Laser Diode and Temperature Controller features a
multitude of safety features to help protect the attached laser diodes and
TEC coolers.
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