Bomb Vessel

The DDS Bomb vessel is unique in that it is the first of its kind and has the following features:

• The vessel is smaller than conventional vessels, which results in a smaller heat capacity. Special attention has been given to a thermally balanced vessel design which has been achieved using computer aided design (CAD) and computer simulation of heat transfer characteristics.
• The vessel has an oxygen volume of 0.22 litres (220ml), which allows for a 0,5gr coal sample at approximately 30MJ/Kg. The temperature sensors are located cylindrically within the vessel walls at eight places.
• The approximate temperature rise of the vessel after burning of 0,5gr benzoic acid is 9 degrees C. Practical tests have shown that up to 0.8gr of benzoic acid can be burnt without affecting the accuracy. Oxygen starvation affects the results with higher charges.
• The vessel is "smart" with a microprocessor built into the base of the unit. All the information pertinent to a vessel is stored permanently inside the vessel i.e. vessel number, calibration, number of firings, date of last reconditioning etc.
• The vessel PCB is only powered up when it is placed in the calorimeter. The consequences of the vessel memory is that any vessel can run in any calorimeter without a new calibration.
• The vessel memory can only be accessed from the PC. The electronics and sensors are vacuum epoxy impregnated to prevent physical damage as well as moisture from entering the electronics.
• The firing wire is semi-permanent and only needs to be replaced when the wire is burnt or damaged.

CAL2k-4 Bomb Vessel Improvements:

• The electronics and sensors are built inside the vessel. The vessel is placed inside the calorimeter and is "docked" in the calorimeter for supervision. The result is a faster more stable temperature reading. The vessel temperature is measured by 8 sensors. The vessels are vacuum expoxy sealed, and no adjustment or maintenance is required.
• The vessel can be operated over a wider temperature range (+10 degrees to +50 degrees C) but it is advised that the vessels starting temperature is within 12 degrees of the ambient (room) temperature.