The Mettler differential scanning calorimeter uses two independent heating systems to act on the sample and reference material respectively, and monitors the temperature difference (Δ T) between the two in real time. When the sample undergoes endothermic or exothermic reactions, the system will automatically adjust the heating power on the sample side to maintain temperature synchronization between the two. At this time, the compensated energy difference corresponds to the thermal effect intensity of the sample; This approach ensures fast response and high baseline stability, especially suitable for capturing dynamically changing thermal events. Use a single heating furnace to simultaneously heat the sample and reference material, measure the temperature difference (Δ T) using a bottom thermocouple, and then convert it into a heat flux difference (Δ H) based on the calibrated heat flux coefficient. This mode has a simple structure and good thermal uniformity, can cover a wider temperature range, and is compatible with multiple sample forms.

Precautions for using Mettler differential scanning calorimeter:

1. Safety regulations

-High temperature protection: During the experiment, do not touch the furnace body, furnace cover, or freshly taken sample crucible, as their surface temperature is high (up to 500 ℃ or above), and tweezers should be used to operate to avoid burns.

-Dangerous gas management: Prohibit the use of flammable, explosive, or corrosive gases; Do not disconnect the air source when the instrument temperature exceeds 100 ℃ to prevent safety accidents caused by cooling system failure.

-Equipment handling restrictions: Due to the heavy weight of the DSC instrument, it cannot be moved alone to avoid personal injury or equipment damage.

2. Operation details

-Cleanliness of crucible: Ensure that the bottom of the crucible used is flat and free of deformation (serrations or bends can affect heat transfer efficiency), and that there are no residual samples or impurities on the inner and outer surfaces. Gently wipe and clean with a soft cloth, do not use hard objects to scratch or damage the surface.

-Sample loading accuracy: Strictly control the sample dosage, with solid samples generally around 20mg and liquids not exceeding two-thirds of the crucible capacity. Avoid spilling the sample on the edge or outside of the crucible, as such behavior may clog the sensor and cause signal distortion.

-Environmental stability: The laboratory temperature should be controlled between 20 ℃ and 30 ℃, and the humidity should be below 75. Significant temperature fluctuations (>5 ℃) can cause baseline drift and can be maintained at a constant temperature through air conditioning; It is recommended to use a dehumidifier in high humidity environments to reduce moisture interference.

3. Maintenance and upkeep

-Regular air burning activation: Before reusing instruments that have not been used for a long time, an air burning procedure (such as setting a temperature of 400 ℃ and a rate of 10 ℃/min) should be performed to remove residual pollutants and restore performance.

-Fault response strategy: When encountering problems such as unstable output signals and large measurement errors, prioritize checking the power connection, component aging, and calibration status. Non professionals are not allowed to disassemble and repair without authorization. They should promptly contact the supplier's technical support team.

4. Experimental optimization techniques

-Repeatability verification: Each group of samples should undergo at least 2-3 parallel experiments to verify the rationality of experimental conditions through data consistency testing.

-Special phenomenon handling: To address issues such as baseline drift and multi peak splitting, efforts can be made to reduce the heating rate, anneal the sample, or enhance drying pretreatment to improve data quality.