Semi-Automatic Gross Calorific Content Analyzer

Semi-Automatic Gross Calorific Content Analyzer

LECO’s AC600 semi-automatic isoperibol calorimeter is ideal for measuring calorific content in solid and liquid fuels, and it sets the bar for future calorimetry equipment. Its semi-automated operation, combined with thermodynamic TruSpeed®, results in a quick study of calorific content and higher instrument throughput without losing accuracy or precision. A redesigned, lightweight combustion vessel with an ergonomic shape ensures simplicity of operation while considerably minimising operator strain.


  • Enhanced automation for added productivity
  • Analysis in as little as 5-minute analysis without compromising accuracy or precision
  • Ergonomically-designed vessel promotes easy vessel handling, while enhancing the heat transfer rate
  • Integrated vessel charging station and depressurization ports equipped with quick-release handles speed vessel charging and depressurization process.
  • Intuitive software provides virtually unlimited storage space, simplified data handling, and compatibility with various Laboratory Information Management Systems (LIMS) 

Theory of Operation

The LECO AC600 semi-automatic calorimeter was created to determine the calorific content of a variety of organic materials, including coal, coke, and fuel oil.

The calorific value of a sample is measured by carefully measuring the heat emitted in a controlled setting after the sample has been burned. The amount of heat emitted is related to the substance’s calorific value.

The sample is placed in a pressured oxygen-filled combustion chamber. Within the instrument known as a bucket, the combustion vessel is automatically lowered into a water bath. An inflated bladder is used to seal the bucket. The jacket is the cavity that surrounds the bucket and is likewise filled with water. The temperature of the water in the jacket is kept at a precise fixed temperature (isoperibol calorimeter system). An electrical thermometer with a resolution of 0.0001 of a degree is used to measure the temperature of the bucket and jacket water after the sample is ignited.

Every second, a reading of the water temperature inside the bucket and jacket is taken. If necessary, the software may rectify the data for spiking, nitrogen, sulphur, moisture, and ash content. There are two methods for examining data. The user can select a basic temperature difference (Delta T mode), in which calorific values are determined by the bucket’s greatest temperature rise. The user can additionally opt to model heat exchange within the AC600 system using a thermodynamic model (TruSpeed mode) created by LECO. The TruSpeed mode accounts for the heat capacity of the system’s components as well as energy transfer corrections within the system.