Testing accelerating rate calorimeter

In a testing context, it refers to the first detection of exothermic-activity on the thermogram. The differential scanning calorimeter (DSC) has a scan rate of I0°C/min, whereas the accelerating rate calorimeter (ARC) has a sensitivity of 0.02°C/min. Consequently, the temperature at which thermal activity is detected by the DSC can be as much as 50°C different from ARC data. 

These tests can also be used to evaluate the induction time for the start of an exothermic decomposition, and the compatibility with metals, additives, and contaminants. The initial part of the runaway behavior can also be investigated by Dewar tests and adiabatic storage tests. To record the complete runaway behavior and often the adibatic temperature rise, that is, the consequences of a runaway, the accelerating rate calorimeter (ARC) can be used, although it is a smaller scale test. 

The Accelerating Rate Calorimeter (ARC ) is another adiabatic test instrument that can be used to test small samples. The ARC with the clamshell containment design can handle explosive compounds. It is a sensitive instrument that can indicate the onset of exothermicity where the reaction mixture can be accurately simulated (HSE 2000). ARC testing results can be used in determining a time to maximum rate of decomposition, as well as in calculating a temperature of no return for a container or vessel with specific heat removal characteristics. Further information and references related to the ARC are given in CCPS (1995a) and Urben (1999). 

Non-adiabatic screening tests such as Carius tube111 and the Accelerating Rate Calorimeter (ARC ), corrected for sample heat losses due to thermal inertia, can also be used for screening. If it is known that the reaction is a vapour pressure system, DSC may be used. 

The thermogram obtained by differential scanning calorimetry (DSC) shows a melting peak at 82.4 °C and an exothermal decomposition peak starting at 160 °C (AHaec = 200 J g ). Tests on an accelerating rate calorimeter (ARC) showed the onset of decomposition at 130 °C, with AHdec = 278 J g", and a final temperature of 179 °C. The accumulated data do not support the originally claimed stability... 

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