CAL3K-A Calorimeter

CAL3K-A Oxygen Bomb Calorimeter System

The CAL3K-A is the companion to the CAL3K-AP, but with external oxygen filling. This instrument was designed for harsh production environments where the automatic filling is not desired. It is faster than the CAL3K-AP, but less automated

Like the CAL3K-AP, it uses a combination of the Isothermal and Adiabatic calorimetry methods, while still using the dry method, i.e. it is waterless. The minimum determination time is down to 4 minutes.

APPLICATION: It excels in a production environment where 12 samples/hour is a standard performance. It applies to all industries and laboratories where a sample can be ignited to determine the calorific energy. Like the CAL3K-AP it applies to food processing, feed stock composition, material and waste analysis, quality control, recycling and alternative energy harvesting.

MORE ACCURATE RESULTS IN MINUTES - The CAL3K-A is our fastest calorimeter systems and is ideal for high sample throughput with more than 12 samples per hour. It uses a combination of the Isothermal and Adiabatic calorimetry methods and is still waterless. The minimum determination time is as little as 4 minutes per sample. The CAL3K-A makes use of the external oxygen filling station, bayonet bomb vessel and air cooler with the calorimeter. The CAL3K-A is the brother of the CAL3K-AP system, the major difference being the manual oxygen filling. This instrument has all the features of the CAL3K-AP, but avoids the potential trouble of leaking oxygen valves and fittings, and the associated maintenance. It can be operated in the Dynamic (Isoperibol), Isothermal, Adiabatic and Experimental modes, but requires calibration in each mode. The vessel is filled with oxygen in an EXTERNAL filling station which has a flow restriction and oxygen filter.


The CAL3K-A conforms to ASTM D240-09, ASTM D5865-12, ASTM D4809-13, ASTM E711-87, ISO 1928-2009, ISO 18125-2017, GB/T213-2008 and DIN 51900-2 international standards. The CAL3K bomb calorimeter uses the isothermal, adiabatic or isobatic calorimetry methods to measure temperature readings and to calculate the result in MJ, BTU or Calories.

The bomb is a self-locking and sealing bayonet vessel with built-in temperature sensors. The vessel is completely removable for easy sample management, cooling, cleaning and maintenance. Multiple vessels can be used in the same calorimeter, each with their own temperature calibration curves. Multiple vessels improve sample throughput and provides a higher redundancy. While one vessel is in the calorimeter, the other can be cooled and prepared with the next sample.

The CAL3K-A calorimeter interfaces with different devices, including PC ( PC Software ), Balance, Printer and Bluetooth (Wireless). The unit also integrates fully with software based laboratory and information management systems (LIMS) and has a statistical print output in addition to the real time output.

The oxygen bomb calorimeter and air cooler are operated together for effective routine sample determination, using 2 or more bomb vessels . It is imperative to use the air cooler for optimum results and faster throughput. The air cooler works in conjunction with the CAL3K-A and gets its cooling instructions from the CAL3K-A. This allows the air cooler to uniquely cool each bomb differently, should it be required. The coolest feature of the air cooler is the ambient temperature compensation, which allows for consistent fast cooling times regardless of the ambient temperature of the laboratory. The air cooler also displays the vessel temperature and the time until the bomb is ready to be used again, all this cooling for only 12 Watts!

The complete CAL3K-A oxygen bomb calorimeter system contains all the parts and consumables necessary to set up the unit. The installation kits included with the setup of the calorimeter contains consumables for approximately 200 samples, depending on the type of sample being analyzed (coal analysis, animal feed analysis). Corrosive and explosive (powder) samples increase the wear and tear on the consumables. Additional consumables can be purchased separately (and in bulk quantities) from our authorized agents.


It is best suited for a production environment with shared oxygen supply (to other users) and robust handling. One external filling station can service multiple CAL3K Calorimeters. The DDS Calorimeters can be used to determine the calorific value of solid and liquid combustibles including oil, coke, volatile fuels, biomass, plastic, coal, animal feeds and foodstuffs. The calorific value of a combustible substance is a critical factor and differs from application to application.

The applications for a DDS Bomb Calorimeter are endless with the common applications being scientific research, university research, coal mines and power stations, alternative energy/recycling, chemical industry, industrial inspection and quality control.


The CAL3K-A uses a combination of the Isothermal and Adiabatic calorimetry methods, while still using the dry method, i.e. it is waterless. The minimum determination time is down to 4.5 minutes.

The vessel is filled with oxygen in and EXTERNAL filling station which has a flow restriction and oxygen filter. The supplied filling pressure is indicated as well as the vessel pressure.

The fastest performance was achieved with one CAL3K-A , 3 vessels and 2 coolers. This is the limit of a single operator. It is possible to run the CAL3K-A Calorimeter with a single bomb vessel and achieve accurate and reliable results.


The CAL3K calorimeter requires a PC keyboard (as seen above/left with the complete system) to enter commands. The lid design has two shocks which open the lid automatically after a determination. The CAL3K-A Oxygen Bomb Calorimeter will be supplied as a complete system which includes the calorimeter, the air cooler , and 2 bayonet oxygen vessels . Other system combinations are possible.

The LCD display has 4 lines, the picture below only showing two of the lines. The first line shows what the CAL3K is doing at present, e.g. what mode the calorimeter is in and what it is doing.


The second line shows the action the operator should take, e.g. "ENTER MASS, INSERT BOMB", etc. The third line is reserved for keyboard command and data entry, e.g. Enter Benzoic Acid Value in MJ. The fourth line gives additional information relating to faults and actions. If the subject help is activated then all 4 lines are used to display the help functions.


This is the CAL3K Oxygen Bomb Calorimeter with the lid open. The new gas shocks allow for automatic opening. The shocks open the lid to 45°C, so that the well can ventilate after each sample determination.

The ATC (Ambient Temperature Control) insulates the oxygen bomb vessel from the outside environment. It contains heating elements designed so that the ATC temperature follows the vessel temperature. as programmed. The ATC is cooled after a determination.

BOMB WELL - The bomb well has a contact arrangement at the bottom to connect to the bomb electronics. The vessel temperature and calibration data are retrieved via this contact.

The electronics compartment is located in the blue side panel of the calorimeter. This electronic compartment contains the control card and the firing circuit. This is what makes everything work. The control card contains all ports (Keyboard, printer, balance, USB, BlueTooth) and is exchangeable for easy maintenance.


The operation is user friendly and easy. Although the CAL3K has close to 100 keyboard commands, only the most used ones are visible without a password. Whenever something is missing (eg Mass), or something ‘unexpected’ happens, or the unit has performed a task, then the operator is informed. In addition a help function is available (F10) which explains the details.

EVENT LOGGING - The CAL3K-A has 63 event classifications and can store a maximum of 6800 logged events. The events can be retrieved via the PC interface and a summary is available on the printer port.

DEFAULT PARAMETER FIELDS - The CAL3K-A has one default parameter field for each mode and one experimental default mode for the user. The experimental mode can be changed via the PC interface. Note that the each operating mode requires a calibration.

FAULT AND FIELD TESTING CAPABILITY - The CAL3K-A and vessel each have a factory and a field test built in. The field test allows the operator/user to test the functionality without any instruments or special connections.


The complete calorimeter system is delivered with installation kits for the calorimeter, air cooler and vessels (for approximately 200 firings).

The CAL3K Bomb Calorimeter Installation Kit includes : Power Supply (3K-SM), Mains Cable 220V (KETTLECORD), Balance Cable (3K-BC), PC Cable USB (USBCABAB), PC Keyboard PS2 (CAL2K-KB), Preparation Stand (3K-4-PS), Stainless Steel Tweezers (TWEEZERS/S/S), Certified Benzoic Acid Tablets (50 x 0.5g tablets per bottle)(CAL2K-4-BA), High Pressure Oxygen Pipe 4mm (4m long, clear)(3K-1-OP), Oxygen Regulator Connection Standard (Quick Fit)(3K-1-RC), Calorimeter o-Rings (1 packet of 5)(3K-1-CF-05), O-Ring retainer for center filling plastic (3K-1-LCR), tool to remove o-ring retainer (3K-1-LCR-TOOL), Vessel Nozzle Kit complete with nozzle and o-ring and nut (3K-4-VN-KT) and printed installation guide (3K-1-INST).

The CAL3K Air Cooler Installation Kit includes : Power Supply (3K-SM) and a Mains Cable 220V (KETTLECORD).

The CAL3K Bayonet Vessel Installation Kit includes : Center Electrode (3K-4-CE), Vessel Nozzle O-Ring (3K-4-VNR), Outside Electrode (3K-4-OE), Crucibles (CAL2K-4-CB-SINGLE), Deflector Plate (3K-4-DP), Firing Wire (3K-4-FW), Firing Cotton Packet (1 packet of 200 threads)(3K-FC), Lid O-Rings (1 packet of 5)(3K-4-LR-5).

The CAL3K Filling Station Installation Kit includes : 2 x Flow Adjustor O-Rings (3K-3-FR), 5 x Nozzle O-Rings (3K-3-NR), 1 x High Pressure Pipe 4mm (2m, clear)(3K-3-OP), 1 x Oxygen Regulator Connection (3K-3-RC) and 1 x Defiller Cap (3K-4-DC).

The following accessories can be added to the CAL3K-A Oxygen Bomb Calorimeter (or purchased separately) :


No temperature control of room/lab required


For different mode and different calorimeters


Temperature accuracy of 10ppm (parts per million)(0.00001°C)


Screen prompts assist with step-by-step instructions to operate the calorimeter


Self-Locking and Self-Sealing manual bayonet bomb vessel


Extensive fault finding and testing


Choose between faster or more accurate determinations


Results in MJ/Kg, BTU/Ib or Callg


No water required to cool the bomb vessel


Extremely accurate (%RSD - 0.05%) determination eliminates multiple sample repeats


Compensation for firing energy and sulphur


Balance interface with baud speed setting


1 Wired (USB) and 2 optional wireless channels


One default setting per mode


Based on drift and time, or time after drift


User Friendly Operation


Operating parameters can be changed via USB interface in experimental mode


For the assignment, scheduling, and tracking of samples


For variable amount of calibration average to suit your application


Operating parameter access is password restricted


Extensive testing and detailed data viewing


Eco Friendly - small carbon footprint. No water, low power consumption


Very low power consumption. No temperature controlling required


Up to 1024 results storage


Extensive temperature range from 0°C to 70°C


Linear temperature sensing with platinum sensors


Intelligent vessel with built-in temperature sensing


Built-in event logging for ~6000 events


Safety checks guarantee the safety of the operator


No Water Bucket. No Spillage.No Measuring


Isothermal, Adiabatic and ISOBATIC (and experimental)


Makes use of an external oxygen filling station

Specification Information
Working (Operating) Temperature 15-70°C
Storage Temperature 0-70°C
Temperature Resolution 0.000001°C
Reproducibility/Repeatability <0.01% RSD
Resolution 0.0001 MJ/Kg
Results per hour 12 samples per hour using 3 bayonet bomb vessels
Measuring range max 99MJ, 99000
Working temperature min 0°C
Working temperature max 50°C
Temperature Measurement Resolution 10ppm (parts per million)
Cooling Medium Air
Type of Cooling Airflow
Oxygen Operating Pressure Max 40 bar
Balance/Scale Interface RS232
Printer Interface RS232
PC Interface USB
Power Input 12W
Interface External Keyboard PS2
Oxygen Filling Manual
De gasification Manual
Halogen (Decomposition) Vessel Yes, optional
Analysis according to DIN 51900 Yes
Analysis according to ASTM D240 Yes
Analysis according to ASTM D4809 Yes
Analysis according to ASTM D5865 Yes
Analysis according to ASTM E711 Yes
Analysis according to ISO 1928 Yes
Dimensions 350mm x 280mm x 240mm
Weight ~12 kg
Permissible Ambient Temperature 0-35°C
Permissible Relative Humidity 80%
RS232 Interface Yes
USB Interface Yes
Voltage 220-240/ 100-120V, 12VDC, 3Amp
Frequency 50/60 Hz
Animal Feed Research

Food calories are measured in KJ/g, the same as combustible calories. However, the process is different, although the outcome is the same : KJ/g or heat, or calories. Animal feed stock relies on the animal digestion (conversion). A calorimeter burns the lot and measures the released heat. Then a calorimeter can't be used to measure feed stock?

View Application
Coal & Coke Analysis

The coal industry is the traditional application of calorimeters because coal has a variety of properties, apart from being black. If the coal is used for steam generation then the calorific value is of paramount importance. The calorific value, short CV, is a measure of how much heat can be extracted from it.

View Application
Explosives Analysis

Only explosives which can be ignited by heat from the calorimeter's firing circuit can be tested in the oxygen calorimeter. Then very minute/small quantities are used for analysis. The calorific value of an explosive is not very high, but the burning speed is.

View Application
Fuel Analysis

As a general rule, volatile fuels are measured very seldom because they are very consistent. However, if the fuel absorbs water, then frequent analysis is called for. Volatile fuel such as alcohol must be prevented from evaporating during the handling process that is from weighing to ignition of the sample.

View Application
Food & Nutrition Analysis

Here is an example of food calories from As the article says : "The method of using a combustion calorimeter to measure food calories is not frequently used today. However, after some considerations it can, and is, used today for checking the production quality of food." Let's look at the details.

View Application
Oil Analysis

Oils are a non-volatile substance. In general they are not measured frequently because they are very consistent and uniform. Other oil properties are more important than the calorific value, such as taste or viscosity. If an oil is measured in an oxygen calorimeter, then the procedure would be the same as a solid substance.

View Application

Simple, we at Digital Data Systems (DDS) have been making calorimeters for the last 40 years. We have a wealth of technical knowledge and calorimeter experience second to none. We are continuously improving our systems with the latest technology as it becomes available, allowing the students to work on a cost effective, easy to use...

View Application
Waste Product Analysis

Heating energy is being dumped on our municipal landfill sites. Our landfill sites are being clogged by plastic waste, which battle to bio-degrade over time. Alternative options for managing plastic waste has been identified as mechanical recycling, cement kilns, power station and energy recovery by incineration. Having plastic on landfill sties should be the last option.

View Application


Other DDS Calorimeter Products in the same range

CAL3K-F Oxygen Bomb Calorimeter System | DDS Calorimeters


A flexible system for low to high throughput without compromising on accuracy and repeatability. It is used in Food/Feed Analysis, Alternative Energy, Scientific Determinations, Coal and Oil Production, research and Quality Assurance. In short : where the calorific value of a solid/liquid sample must be determined.

View Product
CAL3K-U Oxygen Bomb Calorimeter System | DDS Calorimeters


The CAL3K-U is the University Edition in the CAL3K range, mainly suited for universities and educational institutions. It is best suited for a production environment which requires robust, fast, and accurate results. The CAL3K-U Calorimeter can be used in the following educational areas : Thermodynamics Teaching, Combustion Energy of non-gaseous substances, Safety, Research and Quality Control.

View Product
CAL3K-A Oxygen Bomb Calorimeter System | DDS Calorimeters


The CAL3K-AP is suited for a clean and well maintained laboratory with a requirement for very fast and accurate results. The CAL3K-AP Calorimeter uses a combination of the Isothermal and Adiabatic methods.

View Product
CAL3K-A Oxygen Bomb Calorimeter System | DDS Calorimeters


The CAL3K-S is a single vessel system for low sample requirements. It is the most economical calorimeter but matches the accuracy to all other systems. In various system configurations is produces 1 to 4 samples per hour. It works in the ‘DYNAMIC’ mode only, uses no water and requires ~0.3 watt of power, ideal for mobile applications. If you require a couple of samples a day with no frills then this is the instrument for you.

View Product