Introduction

Differential scanning calorimeter has three greatest characteristics of thermal analysis instrument: intelligence, small size, low price. It’s especially designed for measuring oxidation induction time of polyethylene, curing percentage of epoxy, anti-oxide of lubricant etc .

A:The differential scanning calorimeter mainly has the following characteristics：

1.small size;

2.It can quickly rise, drop the temperature;                   

3.high resolution A/D(24 bits) data sampling;

4.intelligence temperature controller of the microprocessor system, the accuracy of the constant

5.temperature can reach to 0.1 over a long period of time because using Pt100 platinum electric resistance and  intelligence temperature controller;

6.adopt numerical air mass flow-meter. Use software to control gas switch and size;

7.high accuracy low drift amplifier;

8 including data processing system and software of. oxidation induction time: collecting, curves, calculating, saving.

B: Main technique specification

1.    DSC scale: ± 10, ± 20, ± 40, ± 100, ± 160, ± 200 mW, and can automatically change.

2.    Temperature range:  RT~450 degrees

Max. temp: 500 degrees

Software temperature control rate: 1～90℃∕min

Heating rate: 1～30℃∕min

3.    Use crucible

 Crucible material and size: Aluminum Φ 6.7 mm × 2.5 mm

4.     Gas control

Gas: nitrogen or oxygen

Gas flow ≤ 100 ml min

Gas pressure: 0.2MPa

5.    Data processing system

    Data collecting, saving, screen displaying and result report: temperature mark and calibration and

     the processing of oxidation induction time

C: The measurement of Polyethylene oxidation induction time

In the test report DSC curves(figure 1 ), it marks A1 point which change nitrogen to oxygen, gives the tangent of the maximum slope when the curve changes significantly, then marks A2 point which is Intersection point of the tangent and the baseline extension line. The time between the two points is oxidation time of sample thermal stability(min)