Thermoline Scientific Equipment TCH-150, Руководство по эксплуатации

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18-5-10 TCH-150 & 460
C-TICK
The equipment referred to here complies with requirement of AS/NZS 1044:1995 electromagnetic
interference (EMI).
PRINCIPLE OF OPERATION:
Read this section in conjunction with figure 1. This will give the operator a guide on how the
cabinet actually controls the conditions within the workspace.
CONTROLS:
Temperature and humidity are controlled by 2 x Eurotherm 3216 digital indicating instruments.
These are mounted on the control panel at the top of the cabinet.
AIR CIRCULATION:
In order to maintain close temperature and humidity tolerances, good air flow is required. Air is
circulated by a centrifugal fan wheel mounted behind the ceiling panel inside the cabinet. This
wheel is driven by a circulating fan motor mounted outside the working area. Air is forced down the
rear air duct, across heating elements, and the water trough, before returning vertically through the
workspace through to ceiling panel for the cycle to start again.
Since the cabinet is not fitted with a refrigeration system there is no active cooling or
dehumidification. In order to compensate for this we provide two adjustable vents on top of the
cabinet, an air inlet and an air exhaust. The operator can adjust these vents to increase or
decrease the amount of ambient air that is mixed with the air inside the cabinet. In this way the
temperature and humidity range of the cabinet can be altered. (See “adjusting the vents” page 15
for further details).
Note: The cabinet is not fitted with a refrigeration system, and it is therfore not possible to
control temperature and humidity inside the cabinet, at levels below the outside ambient
temperature. In fact, the ambient temperature needs to be at least 5ºC lower than the set
temperature in order for the cabinet to properly control the conditions inside the cabinet.
Eg: ambient temperature =25ºC, minimum set temperature = 30ºC.
TEMPERATURE:
The air is heated by means of an element behind the rear air duct, and cooled by the addition of
fresh ambient air through the air inlet vent on top of the cabinet. The temperature controller cycles
the heating on and off to maintain stable temperature.
HUMIDITY:
The air is humidified by a heating element in the water trough in the bottom of the cabinet at the
back.
The air is dehumidified by the addition of fresh ambient air through the air inlet on top of the
cabinet. The humidity controller cycles the trough element on and off to maintain stable humidity.