shelolab SRI21D, Руководство по установке и эксплуатации

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OPERATION
T
HEORY OF
O
PERATION
The SRI diurnal plant growth chamber is engineered to provide a variable
temperature and day – night illumination environment suitable for plant cultivation.
The unit can obtain stable, uniform chamber temperatures, ranging from 0° to 40°C.
Achieving and Maintaining the Temperature Set Point
When the SRI21D is powered, its refrigeration compressor runs continuously. The
chamber temperature controller is wired to a solid-state temperature probe located
in the chamber airstream on the chamber back wall. When the controller detects
that the chamber temperature has dropped below the set point, it pulses power to a
heating element. The element is located adjacent to the compressor chiller coil in an
air recirculation duct at the bottom of the unit.
The processor employs proportional-integral-derivative analytical feedback-loop
functions when measuring and controlling the chamber air temperature. PID-
controlled heating pulse intensities and lengths are proportional to the difference
between the measured chamber temperature and the current set point. The
frequency of pulses is derived from the rate of change in that difference. The
integral function slows the rate of pulses when the temperature nears the set point
to avoid overshooting.
A circulation fan provides even air distribution throughout the chamber, and plays an
important role in maintaining temperature uniformity around the shelf space.
Manual Modes and the Day – Night Auto Cycle
The SRI21D comes from the factory set to operate in manual night mode , which
runs indefinitely with the chamber illumination lights off, and at a steady-state
temperature. A small light will turn on inside the chamber, whenever the chamber
door is opened. The unit is set to 20°C for manual night mode at the factory, but can
be adjusted by the end-user at any time while this mode is active. The unit can also
be switched at any time to run in the indefinite manual day mode with continual
chamber illumination. The day temperature is set to 20°C at the factory but can be
adjusted independently of the night temperature, whenever the unit is operating the
manual day mode.
The end-user can launch a programmable Day – Night Auto Cycle mode with
alternating illumination and darkness phases in the cultivation chamber. This
indefinite cycle has separate temperature set points for its day and night phases.
These set points are independent of the manual mode set points. The SRI21D
comes programed at the factory to start the day phase at 8 AM, Pacific Coast Time
(west coast of the United States, UTC -8), and then start the night phase at 8 PM,
PCT. The temperature set points for the factory cycle are set to 20°C, for both day
and night.
Figure 4: Unit operating
in the manual night
mode, as indicated by
the "6"
Figure 5: Operating in
the manual day mode, as
indicated by the
combination of 2, 3, 5
Figure 6: Operating in the
auto cycle day phase, as
indicated by the
illuminated graph symbol
and “2”