Parr Training
Kripal, Natasha, and Omar from John Morris Group recently underwent a transformative Parr calorimeter training at Adelaide Botanical Garden School, diving into the world of precision and accuracy in calorimetry techniques.
The Parr Calorimeter
The Parr Calorimeter Model 6200, is a microprocessor-controlled, isoperibol oxygen bomb calorimeter that is widely used for both routine and occasional calorific tests. It uses the time-tested Parr 1108 oxygen bomb and oval bucket in a compact calorimeter, producing reliable results with good repeatability, but differing from the 1271 and 6300 Models in that the bomb and bucket both must be removed from the calorimeter and refilled manually for each test, thereby requiring more of the operator's time than the automatic and semi-automatic models.
All sensors, controls and jacketing in the 6200 Calorimeter are built into a single, compact cabinet to provide a self-contained operating unit consisting of:
• A temperature-controlled water jacket with a built-in circulating system and an electric heater.
• An 1108 oxygen bomb with an oval bucket which fits into the insulating water jacket.
• A built-in semi-automatic system for charging the bomb with oxygen.
• A high precision electronic thermometer.
• A bright, color, touch screen display for data entry and operation control.
• Special communication ports for printer, computer and network (LAN) connections.
• Removable compact flash memory card slot for simple program updates and test report archiving.
Precise Electronic Thermometry
Temperatures are measured with a high-precision electronic thermometer using a specially designed thermistor sensor sealed in a stainless steel probe which is fixed in the calorimeter cover. Measurements are taken with 0.0001° resolution over a 20° to 40°C working range, with all readings shown in Celsius.
Effective Thermal Jacketing
Outstanding thermal jacketing is provided by a circulating water system driven by a built-in, high capacity pump which maintains a continuous forced flow around the sides and bottom of the bucket chamber and through the cover as well. The jacket temperature is held constant for isoperibol operation and no water additions or waiting periods are required at the end of a run. A sealed immersion heater and a built-in heat exchanger, both operated by the calorimeter controller, provide precise jacket temperature control.
A Reliable Oxygen Bomb
The Parr 1108 Oxygen Bomb furnished with the calorimeter will safely burn samples liberating up to 8000 calories per charge, using oxygen charging pressures up to 40 atm. An alternate 1108CL bomb with superior resistance to chlorine and halogen acids is recommended for tests involving waste material and chlorinated samples.
A Built-In Oxygen Filling System
To speed and simplify the bomb filling operation, the 6200 Calorimeter has a semi-automatic system for charging the bomb with oxygen. Oxygen from a 1A commercial cylinder is connected to a microprocessor controlled solenoid installed in the calorimeter. To fill the bomb, the operator simply slips the filling hose connector onto the bomb inlet valve and pushes the touch screen to start the filling sequence. Filling then proceeds automatically at a controlled rate to a pre-set pressure. Built- in safety provisions will prevent an accidental overcharge.
