Oxidation inducing instrument

I. overview

 

1.1. Tc-3525 differential scanning calorimeter is a new type of thermal analysis instrument with three characteristics of intelligence, miniaturization and unit combination. It is widely used in the melting, solidification, decomposition, combination, reduction and oxidation, crystallization, phase diagram production, catalyst research and development of materials. It is the main analysis means of organic, inorganic, polymer, mineral, petrochemical, textile, medicine and other aspects, with a convenient computer data processing system. It has a variety of analysis software, such as epitaxial starting point temperature, enthalpy variable, glass transition temperature, enthalpy ratio, oxidation induction period, and various calculation methods of kinetic parameters, and uses various software skills to arbitrarily enlarge or reduce the function, making the overall interface friendly and easy to operate

 

1.2. Dsc-500 differential scanning calorimeter is composed of mainframe, small heating furnace, Microvolt amplifier, a / D converter, data acquisition system, cooling system, gas flow control system, and temperature measurement by thermocouple. The change (heat absorption or heat release) of samples under program temperature control is collected in real time. Platinum resistance method is used for temperature control, and LCD is used for display of mainframe window, Without turning on the computer, the current working condition can be displayed in real time; the panel button can transform the temperature "heating, constant temperature and stop", and the temperature can be tracked by pressing the "heating" button when the temperature is raised twice; the gas flow can be switched and closed by pressing the "nitrogen, oxygen and gas off" button; the computer uses USB communication (desktop computer, laptop computer), printer and other components The components are connected by special connectors for easy installation and maintenance.

 

II. Main technical specifications and instrument use conditions

 

2.1 DSC curve parameters

 

Range: 0 ~ ± 500MW; accuracy: 0.1 μ W; resolution: 0.01 μ W.

 

2.2 temperature parameters

 

Temperature range: room temperature ~ 500 ℃; temperature resolution: 0.1 ℃ (standard metal sample)

 

Heating rate: 1-80 ℃ / min; temperature control mode: heating, constant temperature (fully automatic program control)

 

2.3 use of crucible

 

Aluminum: Φ 6.6mm × 3mm.

 

2.4 gas control

 

Gas: nitrogen, oxygen

 

Gas flow: ≤ 200ml / min gas pressure: 0.2MPa

 

2.5 microcomputer data processing system

 

Data acquisition, storage, screen display and result report: temperature calibration and correction, epitaxial starting temperature, enthalpy variable, glass transition temperature, enthalpy change ratio (reaction conversion rate), oxidation induction period, and processing of dynamic parameters.

 

2.6 normal working conditions of the instrument

 

Room temperature: 15 ℃ ~ 25 ℃

 

Relative humidity: 55-75%

 

Power supply: 220V, 50Hz, power supply needs reliable grounding

 

The workbench where the instrument is placed shall be solid and reliable, and there shall be no strong vibration, strong electricity, strong magnetic field interference and corrosive gas affecting the accuracy and service life of the instrument.

 

2.7 fluctuation range

 

Melting point temperature: ± 0.5 ℃

 

Oxidation induction: constant temperature section: ± 0.3 ℃; gas flow rate: ± 0.1ml/min

 

Enthalpy variable accuracy: ± 1% △ H

 

III. working principle and structure of the instrument

 

Differential scanning calorimetry (DSC) is a technique to measure the power difference between substance and reference substance with temperature under the control of program temperature. Dsc-500 differential scanning calorimeter is mainly composed of heating furnace, main engine, Microvolt amplifier, a / D converter, data acquisition system, cooling system, gas flow control system computer, printer and other components, supplemented by two-way atmosphere switching. The measurement results are processed by computer data processing system.

 

3.1 temperature control system

 

The system consists of temperature controller, thyristor, temperature controlled platinum resistance and heating furnace. The computer gives the temperature signal according to the set program temperature. When the temperature control platinum resistance value deviates from the given resistance value, it indicates that the furnace temperature deviates from the given value. The deviation signal is adjusted by the phase-shift trigger and silicon controlled rectifier to make the furnace temperature track the set value well and produce an ideal temperature curve.

 

3.2 DSC signal measurement system

 

The system consists of differential thermocouple, Microvolt amplifier and a / D converter. The sample holder is composed of a pair of differential thermocouples, alumina rods, etc. before the test, place the sample and the reference material (- alumina powder) in two crucibles respectively, and the heating furnace heats up at a certain heating rate. If there is no thermal reaction on the sample, the DSC curve is a straight line, which is called the baseline. If there is endothermic (or exothermic) reaction on the sample in a certain temperature range, the temperature difference signal is generated After being sent to the microvolt amplifier for amplification, the generated power difference is sent to the A / D converter and output to the computer. After being processed by the computer, the DSC curve is drawn by the display,