The CAL3K system uses the SMART CAL3K bomb vessel. The bomb vessel is the first of its kind, and is the heart of the CAL3K system. Its sophisticated design allows the temperature to be measured to six decimal places in degrees Celsius. The vessel is an intelligent (SMART) vessel with a microprocessor built into its base.
The vessel is capable of recording: firing counts, identification, calibration and reconditioning data. The vessel is the combustion chamber. It is made of stainless steel and tested up to a pressure of 300 atmospheres (4200psi).
The microprocessor in the base of the vessel provides accurate results with each analysis. The complete lid assembly holds the crucible containing the sample for determination. Temperature sensors are built into the wall of the vessel for effective temperature measurement. The vessel is filled with up to 3000Kpa of oxygen for each determination. Measuring calorific values has never been this easy.
The bomb vessel is smaller than conventional vessels, which results in a larger heat capacity. Special attention has been given to a thermally balanced vessel design. Computer aided design (CAD) and computer simulation of heat transfer characteristics is used to achieve this.
The vessel has an oxygen volume of 0.21 liters (210ml), which allows for a 0.5g coal sample at approximately 30MJ/Kg. The temperature sensors are located cylindrical within the vessel walls for accurate temperature measurement.
The approximate temperature rise of the vessel after burning is 0.5g Benzoic Acid is 13 degrees Celsius. Practical tests have shown that up to 0.8g of Benzoic Acid can be burnt without affecting the accuracy. Oxygen starvation affects the results with higher charges.
The heart of the vessel is the intelligent microprocessor built into the base of the unit. All the information pertinent to a vessel is stored permanently inside the vessel. This includes information regarding the: vessel number, calibration, number of firings, date of last reconditioning, temperature rise, etc.
The vessel PCB is only powered up when placed in the calorimeter. The result of the vessel memory is that any vessel can run in any CAL3K calorimeter after it has been calibrated.
The vessel memory can hold up to 7 calibration sets for modes and calorimeters. Each calibration set holds up to 10 calibrations for averaging and history analysis. The vessel outputs temperature, Drift and stability every 6 seconds.
The vessel memory can only be accessed from the PC or the calorimeter. 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.
The Heat capacity is a measurement which describes the amount of energy (heat) needed to raise the vessel temperature by 1 degree. The exact heat capacity is calculated by the CAL3K every 6 seconds after the Start record (parameter) during a calibration and then saved to the vessel as a ‘Bomb Factor’.Learn More
Calorimeters require a high temperature resolution because the result has a high resolution. Despite the inaccuracies in the sample preparation a calorific value (CV) is expressed with 3 or 4 decimal digits. The following components affect a CV of, let's say, 26KJ/g as follows...Learn More
PERFORMING A CALIBRATION
To perform a standard calibration using Benzoic Acid Tablets you will need : A working oxygen bomb calorimeter system connected to a power source, A CAL3K Manual Oxygen Filing Station connected to an oxygen supply (not needed when using the CAL3K-AP Calorimeter)...Learn More