Temperature Control - Thermo Scientific Accela Open Autosampler Hardware Manual

4
Operating the Temperature Controllable Stack Coolers
Temperature Setting, Control, and Alarm

Temperature Control

76 Accela Open Autosampler Hardware Manual
Note Pressing the P button for two seconds or longer will access the programming level.
You can access values, such as OPEr, ConF, OFF, rEG, tune and OPLO, in the menu by
selecting the increment/decrement keys. The user is blocked from all of these menu items.
Leaving the unit untouched for approximately two minutes returns the display to the
current temperature reading information. Turning the device off/on reinstates the
temperature display.
Factory programming blocks the U key.
There are indicators below the display digits that show which relay is in use, OUT1 or
OUT2. The arrows indicate if the unit is heating or cooling.
heating temperature within range of set point
As described in the Specifications section, the cooling/heating capacity of a temperature
control device based on the Peltier technique is always related to room temperature. Only a
limited maximum temperature difference from ambient temperature can be achieved.
PAL stack/tray cooler modules should reach a minimum difference of 14 °C (ΔT).
The controller provides the following temperature setting range:
• Stack cooler: 1 to 45 °C
• Tray cooler: 1 to 70 °C
This wider control range, which is greater than the specification limits (4 to 40 °C and
4 to 70 °C, respectively), provides cooling or heating when the ambient temperature is too
high or too low to easily reach the desired temperature. Heating to a higher temperature could
be important for metabolism or kinetics studies at the human body temperature level of
37 °C.
The cooling option is usually necessary to protect the sample from ambient temperature
during the analytical run time. Stack/tray cooler devices are rarely used to store a sample at a
given temperature for a longer time period.
The measured and displayed temperature represents the temperature in the compartment and
not in the sample liquid. To check the temperature control, an independent temperature
probe is inserted from the front by removing one plastic screw from the front cover. Position
the probe in the middle of the drawer where the tray separator projects up. Tape the probe to
the metal plate of the drawer.
To reach 4 °C in the analytical solution, program a set value lower than 4 °C. The material
used for the sample may be glass, polypropylene, polyethylene, or similar polymer products.
All of these have excellent insulating properties.
cooling
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