- More reliable data and a wider range of application due to the fastest tracking rate up to 200 K/min
- Patented VariPhi® technology can realize low phi test even with a small and safe sample size. Effective detection of both exothermic and endothermic transitions can be achieved by the versatile operating modes on ARC® 254
- Controlled by the same powerful Proteus® software which user can use to operate all other NETZSCH thermal analysis instruments in the lab.
The Accelerating Rate Calorimeter 254 (ARC® 254) provides adiabatic calorimetry data in a safe, controlled laboratory environment. This information helps provide a sound understanding of the fundamental physical processes involved. From this understanding, various safe operating systems and procedures can be developed to mitigate the hazards posed by a reactive system.
The advanced ARC® 254 helps engineers and scientists identify potential hazards and tackle key elements of process optimization and thermal stability. As a highly versatile, miniature chemical reactor, sample can be stirred, material injected, and it can be used for vent studies. The ARC® 254 has been designed to use the traditional 10 ml ARC spherical vessel but can also use the larger 130 ml vessel for low Phi or vent testing.
The Accelerating Rate Calorimeter 254 (ARC® 254) simultaneously measures temperature and pressure. The sealed pressure system also allows the user to evaluate the effect of different gas atmospheres on the thermal stability of the system.
Gaseous reaction products may be analyzed at the end of an experiment to help identify and understand the reaction mechanisms involved.
A single experiment provides data for use in the following:
- Thermal Hazard Evaluation
- Pressure Hazard Evaluation
- Thermokinetic Analysis
User safety is a key objective in the design of model 254. The user is protected by a series of safety systems that are completely independent of the control system. These safety systems work to protect the user in the event that the primary control system fails. Fully computer-controlled and highly automated, the Accelerating Rate Calorimeter (ARC® 254) features a graphical interface that is easy to learn and use.
The system is totally integrated into clean, modern designs in which all routinely used equipment is easily accessible.
- Temperature Range:
RT to 500°C
- Pressure Range (Standard):
0 bar to 200 bar
- Pressure Accuracy:
0.35% full scale (200 bar)
- Sample container:
spherical sample vessel: 1 ml to 130 ml
tube sample vessel: 1 ml to 9 ml
- Test cell materials for spherical vessels with a wall thickness between 0.4 mm and 5.1 mm:
(Volume: 1ml to 130 ml)
- Test cell materials for tube-type vessels with a wall thickness of 0.4 mm and 0.7 mm:
(Volume: 0.1 ml to 9 ml)
- ASTM standard:
based on E1981
- Accessory for battery test
- 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® Patent number US 7,021,820 B2.
The Accelerating Rate Calorimeter heaters (acting as guard heaters) provide a well controlled near-adiabatic environment for the VariPhi®, bomb, and sample system. This allows the sample to be tested in the standard Accelerating Rate Calorimeters (ARC®) operational modes such as Heat-Wait-Search, Iso-Fixed, or Iso-Track.
VariPhi®’s key features in Accelerating Rate Calorimeters mode include:
- The internal heater compensates for the heat lost to the sample bomb during an exothermic reaction.
- The user can define the 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 inertia at which to run the test.
- Tests can be run at the exact thermal inertia at which they will run in the plant or storage container.
- Sample heat capacity is measured as a function of temperature.
- Kinetics that are dependent on thermal inertia, such as competing reactions that cannot be compensated for mathematically, are no longer a problem.
- 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.
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 exothermic and 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 exothermic activity than Heat-Wait-Search tests
- Heat capacity measured directly as a function of temperature
- Enhanced measurements and capabilities over traditional DSC analysis
- Endothermal activity tracking
- Pressure data can be recorded
- Ability to inject sample
- Ability to stir sample
- Ability to set thermal inertia for direct real-world comparison
Through VariPhi® technology , power can be added to compensate to phi = 1.0 (Fires exposure cases should always be run as a phi=1 test) and the calculated fire energy influx can be added directly to the sample at a constant rate.
In this mode, VariPhi® provides the following key features:
- More accurate Fire exposure test case
- Determine Heat of Reaction
- Determine kinetics
- Data is automatically saved to hard-drive throughout the run
- Intelligent Firmware monitors the status and health of key operating sensors and active components
- Safety integrated with hardware and firmware controls
- Seamless integration of data files to Proteus® Analysis, NETZSCH Advanced Software Tools or 3rd party software
Accelerating Rate Calorimeters can be used for the thermal analysis of solid or liquid chemicals or for gas/liquid, liquid/liquid, gas/solid, and liquid/solid mixtures. They can also be used for process simulation of batch and semi-batch reactions, battery testing, fire exposures, emergency relief venting, and physical properties measurement.
Lithium Ion is becoming the technology choice for HEV, PHEV, as well as many stationary applications. The White Paper explains how the unique combination of adiabatic and isothermal testing are best suited for looking at thermal runaway of cells within packs for the design of safety features and to minimize the risks of internal shorting leading to thermal runaway.