The vessel is the heart of the calorimeter and features a printed circuit board containing; a microprocessor, memory, temperature sensors and other electronics, which are built into the base
The calorimeter vessel features safety standards, data tracking requirements and reliability.
The solid-state temperature sensors are strategically placed around the outer wall of the vessel and are embedded into the aluminum skin of the unit.
The position of the sensors integrates the various temperature readings obtained from the outer surface of the stainless steel core.
The way in which a sample burns causes a varying heat pattern transfer to the core.
An added benefit is that the memory of the unit is permanent, requiring no battery to retain the data.
As there are no serviceable parts in the electronics of the vessel (they are all surface mount devices) the board is fully encapsulated in resin.
This ensures that the electronics are protected from both moisture and any mechanical damage.
All the information required to operate the vessel is stored in its own memory, and as a result, any vessel can be used in any calorimeter without having to do a new calibration.
In theory, up to 255 vessels could be used on a single calorimeter and although this may not be practical for smaller laboratories, in larger commercial laboratories it does allow for freedom of optimization for both calorimeter and vessel usage.
The memory of the vessel can store the manufacturing data and serial number, reconditioning data, customer data, firing count and status, ten calibration curves, and vessel number.
The manufacturing data and serial number, reconditioning data and customer data can only be entered or changed by Digital Data Systems at its factory.
The customer cannot change this in any way - this is for safety reasons.
The firing count keeps track of the number of firings that the vessel has done since manufacture or the last reconditioning.
Once this count reaches a preset level (factory set is usually 5000) the vessel is 'turned off' and prevented from doing any further firings until it has been inspected and reconditioned.
This is done by an authorized service engineer and after inspection; the service engineer can extend the preset level if the vessel is found to be in a serviceable state.
If the vessel is reconditioned the counter is reset and the date is entered into the vessel memory.
Once again the customer cannot change the count in any way - this is for safety reasons.
A warning is displayed when the count is near to the preset turn off level.
The ten calibration curves can either be individual curves or standard deviation calculated curves or a combination of both.
Any curve can be selected as the active curve.
The vessel number can be set by the customer and is used by the calorimeter to identify a vessel.
The vessel number is part of the result string of a determination.
This allows for tracking and analysis of determinations to be done on a specific vessel.
