CAL3K-U Calorimeter

CAL3K-U Oxygen Bomb Calorimeter System

A UNIVERSITY FOCUSED BOMB CALORIMETER – Our most affordable entry-level system is specifically manufactured for university applications. If you require fast, robust, and accurate results, but need to analyze less than 8 samples per hour, this is the calorimeter for you.

APPLICATION : 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 is ideal for thermodynamics teaching, analyzing the combustion energy of non-gaseous substances, safety applications, and for research and quality control. The system includes the manual filling station, bayonet bomb vessel and air cooler with the calorimeter.

CAL3K-U Oxygen Bomb Calorimeter | DDS Calorimeters
CAL3K-U Oxygen Bomb Calorimeter | DDS Calorimeters
CAL3K-U Oxygen Bomb Calorimeter | DDS Calorimeters
CAL3K-U Oxygen Bomb Calorimeter | DDS Calorimeters
CAL3K-U Oxygen Bomb Calorimeter | DDS Calorimeters

The CAL3K-U conforms to ASTM D5865-12, ASTM D4809-13, ISO 1928-2009, and DIN 51900-2 international standards. The CAL3K-U bomb calorimeter works in a DYNAMIC (Isoperibol) method.

The traditional CAL2K-4 bomb vessel has been replaced with 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.

The CAL3K-U 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).

The oxygen bomb calorimeter and air cooler are operated together for effective routine sample determination, using 2 or more bomb vessels. It is recommended to use the air cooler for optimum results and faster throughput.

The complete CAL3K-U 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). Other samples like oil, might use more consumables as they are corrosive and could cause wear and tear. Additional consumables can be purchased separately (and in bulk quantities) from our authorized agents.


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 can be used in the following educational areas :

Thermodynamics Teaching

Combustion heat release, heat transfer, measuring heat, heat loss, temperature equilibrium, heat conduction

Combustion energy of non-gaseous substances

Renewable energy resources, traditional energy sources
Ethanol, waste, plastics, animal feed and products


Combustion energy of our surroundings : wall paint, car seats, ceilings, clothing
Composite material research


Improving animal husbandry, more energy for the buck, alternative energy, oils
Energy absorption or conversion

Quality Control

Food : an alternative method of assuring consistency of consumed substances

The CAL3K-U can be applied to different industries, mainly focusing on universities. To read more about the different applications visit our Applications section.

View All Applications


The CAL3K-U uses the dynamic method of determination, while still using the dry method, i.e. it is waterless. The minimum determination time is up to 6 minutes.

There is a need for an external oxygen filling station to fill the vessel. The pressure is regulated to the standard 30 bars and the regulated pressure and the vessel filling pressure is indicated.

The fastest performance was achieved with one CAL3K-U Calorimeter, 3 Manual Bayonet Vessels and 2 Air Coolers. This is a full occupation for a single operator


The CAL3K-U calorimeter requires a PC keyboard to enter commands. The CAL3K-U Oxygen Bomb Calorimeter will be supplied as a complete system which includes the calorimeter, the air cooler and 2 manual bayonet oxygen vessels.

The LCD display has 4 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-U Oxygen Bomb Calorimeter with the lid open. The environmental isolation to the ambient is provided by POLYSTYRENE.

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 from this contact.

The electronics compartment is located inside at the rear panel. This electronic compartment is the “brain” of the calorimeter, as we like to call it. This is what makes everything work. There you will find the firing circuit and the ECU card, which can easily be removed, making maintenance quick and easy.


The CAL3K Calorimeter has some added features which will make the operation of the oxygen calorimeter a lot easier and user friendly. Every step in the determination of the calorific value of the sample has a help screen attached and operator prompts assist with step-by-step instructions to operate the calorimeter.

EVENT LOGGING – The CAL3K-U has 63 event classifications and can store a maximum of 6800 logged events.

DEFAULT PARAMETER FIELDS – The CAL3K-U has 1 default parameter field for each mode. All fields are for different operation and operating modes.

FAULT AND FIELD TESTING CAPABILITY – The CAL3K-U 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-U Oxygen Bomb Calorimeter (or purchased separately) :


Extensive testing and detailed data viewing


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


Safety checks guarantee the safety of the operator


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


Very low power consumption. No temperature controlling required


Up to 350 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


No Water Bucket. No Spillage.No Measuring


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 9 samples per hour using 3 bayonet bomb vessels
Measuring range max 99MJ, 99000J
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


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-AP Oxygen Bomb Calorimeter System | DDS Calorimeters


The CAL3K-AP is best suited for a clean and well maintained laboratory with a requirement for very fast an accurate results. The CAL3K-AP Calorimeter uses a combination of the Isothermal and Adiabatic methods, while still using the dry method, i.e. it is waterless.

View Product

CAL3K-A Oxygen Bomb Calorimeter System | DDS Calorimeters


The CAL3K-A is best suited for a production environment with shared oxygen supply (to other users) and robust handling. One external oxygen filling station can service multiple CAL3K Calorimeter Systems. The DDS Calorimeters range can be used to determine the calorific value of solid and liquid combustibles including oil, coke, volatile fuels, biomass, plastic, coal, animal feeds and food stuffs.

View Product