Based on the highly successful Drycal, which has become the largest selling calorimeter in South Africa, the TwinCal incorporates two calorimeter sections into a single unit, mounted on the right of the instrument.
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A highly effective Oxygen charger unit that reduces operator involvement in charging the bomb is located between the calorimeter section and the Bomb Cooling/Washing tower, located on the left side of the instrument.
An analytical balance and an all-in-one computer, which carries the analytical program, stands to the left of the instrument.
The TwinCal uses identical bombs to the Drycal, which have established a very high reputation for safety and reliability. The operator will start a determination in the usual way by weighing the sample into a Stainless Steel crucible, adding the supplied length of cotton, then lowering the bombcap into the bomb and locking the cap. He, or she, will then place the bomb onto the Oxygen Charger and press the top plate downward. Oxygen will then flow into the bomb until the pre-set pressure is reached, when the locking mechanism will be automatically activated and the bomb released. The charged bomb will then be lowered into the left calorimeter (Cal 1) section and the lid closed to start the automated determination process.
While that process is underway, the operator will prepare and load a second bomb into the right calorimeter section (Cal 2), and then a third bomb to be ready to go into Cal 1 as soon as the first determination is completed.
When the determination in Cal 1 is complete, the operator will be remove and depressurise the bomb by rotating the locking pin to the open position. The bomb will then be inverted and loaded into the Cooling/Washing well on the left, where it will be cooled and internally washed to remove acid and ash residues. The bomb cap will be lowered into the bombcap cooler well. When the cooling and washing is complete as shown by an LED on the cooling station the bomb will be ready for the next sample.