Thermo Scientific 10519, Инструкция по эксплуатации

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3-1
CHAPTER
3
OPERATION
In order to fully understand the operation of the Model 200L Single Dilution Probe
Controller, a general knowledge of the electronics, flow, and subassemblies is
recommended. A better understanding of the components themselves will allow the user
to correctly change parts or subassemblies more efficiently.
ELECTRONICS
The relay and switch boards are the primary active electronic circuit boards mounted in
the controller unit. A DC voltage of +24 is utilized from the relay board to activate the
solenoid valves. The position of the rotary switch on the front panel determines which
solenoid valve or valves are activated in order to allow air or gas flow through the Model
200L Single Dilution Probe Controller.
The rear terminal board delivers dry contact
status output which can be connected to a data acquisition unit. The controller can be
activated remotely by a data acquisition unit or by solid state relay configurations.
RELAY BOARD
The relay board su24 Volts to the solenoid valves, depending upon the position of
the switch. The relay board is part of the regulator-relay board assembly (Figure 3-1).
Three ribbon cables are attached to the relay board. One of the cable assemblies is
connected to the switch board assembly and the other two are connected to the rear
terminal board. The relay board controls the position of the valves and provides solid
state contacts to the rear connector board. The voltage from the transformer delivers
approxi20 Volts AC, which is than converted to +24 Volts DC by four diodes
(see appendix B for relay board schematic for details). The +24 Volts DC goes through
the relay board and is delivered to the Switch Board Assembly. The switch from the
switch board assembly directs the +24 Volts DC to the appropriate solid state relay. A
¼ amp fuse is used for safety prevention of surge current while the unit is in the sample
mode.