Accelerating Rate Calorimeter 244 (ARC^®)

VariPhi is a controlled variable DC heater used in Accelerating Rate Calorimeters (ARC^®) to provide the most accurate simulation of real-world thermal environment.

VariPhi’s sophisticated calibration software regulates and records the amount of energy supplied by the internal heater.

VariPhi enables precise measurement of heat, pressure, and activity within a sample, avoiding the need for complicated mathematical corrections.

VariPhi in Accelerating Rate Calorimeters (ARC^®)

The Accelerating Rate Calorimeter heaters (acting as guard heaters) provide a well controlled near-AdiabaticAdiabatic describes a system or measurement mode without any heat exchange with the surroundings. This mode can be realized using a calorimeter device according to the method of accelerating rate calorimetry (ARC). The main purpose of such a device is to study scenarios and thermal runaway reactions. A short description of the adiabatic mode is “no heat in – no heat out”.adiabatic environment for the VariPhi bomb, and sample system. This allows the sample to be tested in the standard Accelerating Rate Calorimeters operational modes such as Heat-Wait-Search (HWS)Heat-Wait-Search is a measurement mode used in calorimeter devices according to accelerating rate calorimetry (ARC).Heat-Wait-Search, Iso-Fixed, or Iso-Track.

VariPhi’s key features in Accelerating Rate Calorimeters (ARC^®) mode:
 

• The internal heater compensates for the heat lost to the sample bomb during an exotherm.
• The user can define the Thermal inertiaThe thermal inertia is equivalent to the  PHI-factor. Both describe the ratio of mass and specific heat capacity of a sample or sample mixture compared to that of the vessel or sample container.thermal inertia or PHI (Φ) for the test. The heater returns all or part of the heat lost to the bomb wall to the sample. A user can define the exact Thermal inertiaThe thermal inertia is equivalent to the  PHI-factor. Both describe the ratio of mass and specific heat capacity of a sample or sample mixture compared to that of the vessel or sample container.thermal inertia at which to run the test.
• Tests can be run at the exact Thermal inertiaThe thermal inertia is equivalent to the  PHI-factor. Both describe the ratio of mass and specific heat capacity of a sample or sample mixture compared to that of the vessel or sample container.thermal inertia at which they will run in the plant or storage container.
• Kinetics that are dependent on Thermal inertiaThe thermal inertia is equivalent to the  PHI-factor. Both describe the ratio of mass and specific heat capacity of a sample or sample mixture compared to that of the vessel or sample container.thermal inertia, such as competing reactions that cannot be compensated for mathematically, are no longer a problem.
• Thermal inertiaThe thermal inertia is equivalent to the  PHI-factor. Both describe the ratio of mass and specific heat capacity of a sample or sample mixture compared to that of the vessel or sample container.Thermal inertia can be corrected without having to extrapolate kinetics from overlapping and multiple reactions.
• Data obtained will directly correspond to actual run or storage conditions making it easier to relay the information to non-calorimetry specialists.

VariPhi in Scanning Mode

By using VariPhi as an additional heater, the user can run ramp tests with the Accelerating Rate Calorimeter (ARC^®) that deliver improved information about the activity in a sample.
By operating in scanning mode, VariPhi can measure ExothermicA sample transition or a reaction is exothermic if heat is generated.exothermic and EndothermicA sample transition or a reaction is endothermic if heat is needed for the conversion.endothermic activity, heat capacity, and pressure within a sample, faster and more cost effectively than a standard differential scanning calorimeter.

In scanning mode, VariPhi provides the following key features:
 

• Faster data collection on ExothermicA sample transition or a reaction is exothermic if heat is generated.exothermic activity than Heat-Wait-Search (HWS)Heat-Wait-Search is a measurement mode used in calorimeter devices according to accelerating rate calorimetry (ARC).Heat-Wait-Search tests
• Enhanced measurements and capabilities over traditional DSC analysis
• Endotherm activity
• Pressure data
• Ability to inject sample
• Ability to stir sample
• Ability to set Thermal inertiaThe thermal inertia is equivalent to the  PHI-factor. Both describe the ratio of mass and specific heat capacity of a sample or sample mixture compared to that of the vessel or sample container.thermal inertia for direct real-world comparison