ARC Testing (Accelerating Rate Calorimetry)
ARC Testing (Accelerating Rate Calorimetry)
ARC Testing (Accelerating Rate Calorimetry)
Quantify thermal stability and runaway behavior to support safer scale-up and operation.
Many chemical processes involve materials that can become unstable as temperature rises. When a secondary reaction accelerates, the result can be rapid heat release and fast pressure build—exactly the kind of escalation that turns a small upset into a major event.
ARC testing provides measured, quantitative data on how a sample behaves as it transitions from stable to self-heating. That data helps teams make confident decisions about operating limits, storage conditions, and mitigation strategies when screening indicates a potential hazard.
Why ARC Testing is Used
ARC testing is designed to capture behavior that simpler thermal screens can miss—especially when you need to understand how quickly an exotherm develops and what happens to pressure as temperature increases.
Use ARC testing when you need to:
- Confirm or refine thermal stability concerns identified during screening, including determining Time to Maximum Rate data
- Understand self-heating and escalation potential during realistic upset scenarios (e.g., loss of cooling or external heat input)
- Evaluate pressure behavior for systems that evolve gas during decomposition or reaction
- Support downstream process safety work by grounding decisions in defensible data
Need to go beyond standard conditions? DEKRA is equipped to support complex ARC work, including:
- Custom atmospheres
- Gaseous or volatile samples (as appropriate to the method and safety controls)
- Hazardous, pyrophoric, or otherwise difficult-to-handle materials
- Non-routine constraints that require a tailored approach
Our team can help you define a test plan that fits the material, the question you need answered, and the decisions you’re trying to enable.
What ARC Testing Measures
ARC testing generates a time-based profile that can be used to evaluate:
- Onset of self-heating and exothermic activity (including decomposition onset)
- Temperature rise behavior across the event (including rate information)
- Pressure evolution as temperature increases (including rate information)
- Gas generation trends, where permanent gas is formed during decomposition
- Inputs that may support SADT evaluation for transportation and classification needs (when appropriate for the system and test design)
How the Test Runs
ARC testing heats the sample in controlled increments. After each increase, the system pauses and monitors the sample for signs of self-heating. If self-heating is observed, the instrument follows the event through completion under near-adiabatic conditions. If the sample remains stable, the test advances stepwise until exothermic activity begins.
This approach is particularly valuable for reactions that accelerate over time, because it captures not only “if” an event occurs, but also the shape and pace of the event.
Using ARC Data in a Broader Risk Picture
ARC results become even more useful when integrated with other reaction hazards testing. Together, these datasets can help characterize the risk associated with credible upset conditions and support decisions about safeguards, relief design inputs, and operating boundaries.
ARC data may also support evaluation of self-accelerating decomposition temperature (SADT) considerations relevant to DOT shipping classification when applicable.
Supplemental Services
Need more than the baseline dataset? DEKRA can extend the value of your ARC work with additional support such as:
- Post-test headspace analysis via Gas Chromatography
- SADT-focused evaluation support (where applicable)
- Vapor pressure analysis
- Phi-correction of data
- DIERS support
