Information on the most widely used ASTM standards within the materials testing industry
Model: UT2114; ISO 1138
Coulometric fully automatic sulfur analyzer is a high-end instrument in the sulfur analyzer series. This instrument features computer control and a horizontal structure, suitable for users with many samples and few lab personnel. It is designed with 7, 20, and 24 samples, and the entire testing process can be completed unattended and automated.
According to the coulometric titration method in GB/T214-2007 "Methods for Determination of Total Sulfur in Coal," the system strictly follows national standards and automatically completes the determination of total sulfur content. It is widely used in coal testing, brick factories, stone heating, electric power, coking, chemical engineering, scientific research, food, and other industries. In long-term practical experiments, for customers' high-sulfur samples, the original circuit was upgraded to a dual-coulometric electrolytic cell integration, making the integration more complete. It performed excellently in testing high-sulfur ore samples such as iron concentrate, copper concentrate, and lead concentrate. Especially in terms of stability and repeatability!
ISO 1138 Rubber compounding ingredients — Carbon black — Determination of sulfur content
ASTM D1619 Standard Test Methods for Carbon Black—Sulfur Content
General introduction
UnitedTest manufactures high-end coulometric fully automatic sulfur analyzers compliant with ISO 1138 and GB/T214-2007 standards, featuring unattended multi-sample testing and upgraded dual electrolytic cell design for stable total sulfur detection in coal, ore and industrial materials.
The coulometric fully automatic sulfur analyzer is a high-end precision testing instrument within the professional sulfur analyzer series, widely adopted for accurate total sulfur content determination across industrial and laboratory scenarios. Adopting an optimized horizontal structural design and intelligent computer automatic control system, this sulfur testing machine perfectly suits laboratories with large sample volumes and limited staffing, greatly improving testing efficiency and reducing manual operation workload.
This automated analyzer supports 7-sample, 20-sample, and 24-sample batch testing modes, enabling fully unattended and automated completion of the entire sulfur detection workflow. Strictly complying with the coulometric titration method specified in GB/T214-2007 Methods for Determination of Total Sulfur in Coal and meeting ISO 1138 standard requirements, the equipment delivers precise, standardized total sulfur measurement results for various solid samples.
To adapt to high-sulfur sample testing demands, UnitedTest has upgraded the core circuit structure with an integrated dual-coulometric electrolytic cell design, achieving more thorough and stable electrolytic integration. This optimized structure delivers exceptional performance for high-sulfur ore sample testing, including iron concentrate, copper concentrate, and lead concentrate, with outstanding testing stability and superior data repeatability compared with traditional sulfur analysis equipment.
Key Features
(1) This instrument is equipped with computer-controlled automatic control to complete the entire sample inspection process
(2) The sample feeding structure uses a stepper motor for precise positioning. If abnormal operation occurs, the sample feeding rod will automatically detach, preventing damage to the quartz boat and reducing tubes inside the furnace
(3) Horizontal high-temperature cracking furnace, making operation more convenient
(4) Number of test samples: 1~20 (during testing, you can dynamically add samples, queue up and requeue, and dynamically adjust the sample preparation queue and order). The entire testing process after loading can be unattended and automatically completed by the instrument
(5) User-friendly human-machine interface, making it easy for operators to learn and use
(6) Constant current source electrolysis method, with coulometric titration integral calculation implemented by program. The program comes with an overall coefficient calculator, and system errors are self-corrected by the software. Test results comply with national standards, with good repeatability and high accuracy
(7) The system is designed with a fault detection task program and features fault diagnosis and alarm prompts. Additionally, there is a debugging menu for convenient fault diagnosis and troubleshooting
(8) Automatically check whether the airflow in the purification system is sufficient, and promptly remind the operator. Prevent deviations in results caused by air leakage or blockage
(9) Microcomputer testing software supports Windows platform, can be connected to electronic balances, automatically transmits weighing data, and supports remote data sharing via network, making data sharing convenient for sharing
Equipment for measuring the total sulfur content in coal, coke, petroleum, steel, and various minerals
The Coulometric sulfur analyzer is a device that uses the Coulometric titration method (also known as the coulometric titration method) to measure the total sulfur content in coal, coke, petroleum, steel, and various minerals. It is used in laboratories of coal, electricity, chemical, building materials, metallurgy, geological exploration, commodity inspection, and environmental protection testing. Its measurements comply with the requirements of the national standard GB/T 214-2007 "Methods for Determining Total Sulfur in Coal," and the relevant technical conditions follow the national standard GB/T 31425-2015.
Modern coulometricic sulfur analyzers typically use microcomputers or microprocessors for intelligent control, with functions such as automatic titration endpoint determination and automatic control of the electrolysis process. Some models support batch testing, with a high degree of automation, enabling automatic sample feeding, data processing, and result printing. The instrument uses micro-coulometric analysis technology, offering stable performance and easy operation.
The Coulometric sulfur analyzer is a device based on the coulometric titration method for measuring total sulfur content. Its structure mainly consists of a tubular high-temperature furnace, electrolytic cell and electromagnetic stirrer, coulometric integrator, sample feeding program controller, air supply and purification device, and electronic analytical balance.
The tubular high-temperature furnace can heat above 1200°C and has a (1150±10)°C high-temperature constant temperature zone at least 70mm long, equipped with a platinum-rhodium-platinum thermocouple temperature measurement and control device. The furnace is equipped with reducing combustion tubes resistant to temperatures above 1300°C. The electrolytic cell is (120-180) mm high, with a capacity of no less than 400mL, containing platinum electrolytic electrodes of about 150mm² and platinum indicator electrodes of about 15mm². The indicator electrode response time should be less than 1s, and the electromagnetic stirrer speed is about 500 r/min and can be continuously adjusted. The integration linear error of the coulometric integrator within the electrolytic current range (0-350) mA should be less than 0.1%, and it is equipped with a 4-6 digit digital display or printer. The sample feeding program controller can flexibly move forward and backward according to the specified program.
The air supply and purification device consists of an electromagnetic pump and a purification tube, with an air supply rate of about 1500mL/min and a pumping volume of about 1000mL/min. The purification tube contains sodium hydroxide and color-changing silica gel. The sensitivity of the electronic analytical balance is 0.1mg. Modern coulometricic sulfur analyzers often use microcontroller control systems to handle the heating process of the high-temperature furnace, control the heating speed, collect measurement data, and send commands to complete the experimental process.
ISO 1138 Rubber compounding ingredients — Carbon black — Determination of sulfur content
ASTM D1619 Standard Test Methods for Carbon Black—Sulfur Content
GB/T 3780.14 Carbon black—Part 14:Determination of sulfur content
The core product standard for Coulometric sulfur analyzers is the "Technical Specifications for Coulometric Sulfur Analyzers" (GB/T 31425-2015). This standard was released on May 15, 2015, and implemented on July 1, 2015, with the National Coal Standardization Technical Committee as the responsible unit.
The instrument's determination of total sulfur content in coal is mainly based on the national standard GB/T 214-2007 "Methods for Determining Total Sulfur in Coal."
When applied in petrochemical and related fields, other standards must also be referenced, such as SH/T 0253-92 "Determination of Total Sulfur Content in Light Petroleum Products (Electricity Method)", GB/T 11061-1997 "Determination of Total Sulfur in Natural Gas - Oxidized Microcoulometric Method", and SH/T 0222-1992 "Determination of Total Sulfur Content in Liquefied Petroleum Gas (Electricity Method)", among others.
1. Principle of analysis:
Various forms of sulfur in coal are combusted and decomposed in purified air under high temperatures not lower than 1150°C and catalytic action. The resulting sulfur dioxide is titrated by coulometricic titrations using iodine and bromine produced by electrolyzing potassium iodide and potassium bromide solutions. The electricity consumed by electro-producing iodine and electro-bromine is calculated by a coulometric integrator, which calculates the milligrams and percentage of sulfur content in the coal.
Sulfur (mg)
S (%) = —————————— ×100%
Sample weight (mg)
2. Program Control Principles:
The entire process of the instrument is controlled automatically by a microcomputer; after the machine is powered on, keys can be entered via the keyboard
date and sample weight (3 digits). Press the start button once, and the motor rotates forward, driving the sample feeding rod forward. When it reaches 700°C, the feeding mechanism automatically sends a signal to the computer, stopping the machine and delaying it for 45 seconds. Then, the computer sends a signal to make the motor rotate forward and drive the feeding rod to continue moving forward. At 1150°C, the feeding mechanism automatically sends this signal back to the computer, causing the motor to stop; It automatically determines the end point of the electrolysis, then sends a signal to reverse the motor, pulling the feeding rod back to its original position. The motor stops, ending the entire testing process and printing the test data.
3. Principle of the endpoint and electrolytic current controller
When the electrolyte is at the endpoint, i.e., in equilibrium, the potential between the indicator electrodes is close
At zero, the electrolysis of the electrolytic electrode ends. When S02 enters the electrolytic cell, it disrupts the electrolyte's electricity
When deequilibrium, the potential between the indicator electrodes rises, the electrolysis is activated, and the electrolytic electrode begins to perform electrolysis.
Sulfurous acid and sulfuric acid produced by oxidizing and titrating SO2 with water using electro-generated iodine and electro-bromine are metrified. The magnitude of the electrolysis current is determined by the potential of the indicator electrode. When the titration endpoint is reached again, the potential between the indicator electrodes returns to nearly zero, the electrolytic current on the electrode immediately reaches zero, and electrolysis ends
The Coulometric sulfur analyzer is mainly used to determine the total sulfur content in coal, steel, and various minerals. It is a commonly used instrument in laboratories of coal, electric power, chemical, building materials, metallurgy, geological exploration, commodity inspection, and environmental protection testing. This instrument is also suitable for determining sulfur content in materials such as heavy oil, lubricants, coal, coke, various minerals, and petrochemical products.
This instrument complies with standards such as SH/T 0253 "Determination of Total Sulfur Content in Light Petroleum Products (Electricity Method)" and GB/T 11061 "Determination of Total Sulfur in Natural Gas - Oxidized Microcoulometric Method."
Main Technical Specification
| Sulfur measurement range | 0—99.99%, with automatic correction of test results |
| Test duration | self-determined within 3 minutes to 6 minutes 30 seconds |
| Sulfur measurement resolution | 0.001 mg |
| Sample weight | (50±0.02) mg; High sulfur content samples can be weighed sparingly, low sulfur content samples can be weighed multiple times, making analysis convenient |
| Sample quantity | 1-24 per batch |
| Power supply | 220V ±10% 50Hz |
| Power consumption | 50VA |
Main Accessories
Computer: 1 set;
Printer: 1 unit (optional);
Carbon silicon tube: 1 piece;
Electrolytic cell: 1 piece;
Quartz tube: 1 piece;
Quartz boat: 2 pieces;
Porcelain boat: 10 pieces;
Sample delivery rod: 2 pieces;
Thermocouple: 1 piece;
Drying tube: 2 pieces;
0# stopper: 2 pieces;
7# stopper: 2 pieces;
Potassium iodide: 1 bottle;
Potassium bromide: 1 bottle;
Trioxide: 1 bottle;
Standard coal sample: 1 bottle;
Degreaser cotton: 1 pack;
Spoon: 1 set;
Tweezers: 1 set;
Color-changing silicone: 1 bottle.
Standard
ISO 1138 Rubber compounding ingredients — Carbon black — Determination of sulfur content
ISO 1138 defines two test approaches to measure total‑sulfur mass‑fraction for all grades of rubber‑grade carbon black.
Two methods — a classical combustion furnace method (Method A) operating at 1425 °C with iodometric titration, and an automatic analyser method (Method B) performed in accordance with ISO 15671. Because of better safety and precision, Method B is the preferred method; Method A remains acceptable when automatic equipment is not available.
ASTM D1619 Standard Test Methods for Carbon Black—Sulfur Content
ASTM D1619 is the international reference method for measuring total sulfurin carbon black. It defines two independent routes —Method A, high-temperature combustion at 1350 °C with infrared absorption detection, and Method B, X-ray fluorescence (XRF).
Require More Customized Solutions?