Advanced Instruments 3300, User Manual

Page: 25 / 77

Application Board: The application board contains the circuits for con-
trolling and interfacing with the other subsystems such as the keypad,
display, cooling assembly, RS-232, printer and barcode ports, etc. The
application board also contains two 20-bit A/D converters for reading
the sample and block probe thermistors.
Sampler (Figure 1)
The sampler is a specialized pipette which contains and positions a very
specific volume of sample for each test. The sampler consists of the
pipette body and disposable plastic sample tip that must be replaced
after each test.
Operating cradle (Figure 1)
The operating cradle is a sliding mechanism that guides and introduces
the sampler to the freezing chamber.
Cooling chamber & measurement and control circuits:
A high-reliability thermoelectric module controls cooling chamber tem-
perature, while a thermistor sample probe measures the dynamic tem-
perature of a sample. Test results, based on the freezing point of the
sample, are automatically sent to the instrument’s display.
Display panel (Figure 1)
The display panel displays:
• Test status and results.
• Status messages when the instrument is turned on or when functions are
selected.
• Pertinent error messages when fault conditions occur. (Messages longer
than 24 characters wrap to the second line.)
Multifunction soft keys (Figure 1)
Other than starting osmolality tests, which are initiated by the operating
cradle, all operator communication to the Model 3300 is accomplished by
means of the two multifunction soft keys.
7
Instrument Operation