Sulfur powder oil content test (desktop nuclear magnetic resonance analyzer)

Background introduction:

In the production process of chemical powders (such as sulfur), a certain amount of oil is added according to the requirements of product quality and characteristics to enhance product performance and facilitate production and processing. The powder also contains moisture. The content of these liquids in the powder is an important parameter that affects product quality. To ensure stable product quality, accurate and rapid measurements are required. Low field nuclear magnetic resonance can quickly complete oil and water content testing, and the sample preparation process is very simple, providing the possibility for quality inspection and quality control in industrial production processes.

Introduction to Traditional Testing Methods:

The traditional method is to use solvent extraction to detect the oil content in sulfur. This method has a complex and time-consuming detection process, requires professional technicians to operate, and has a large human error. In addition, the extraction solution is a toxic reagent, which poses a risk to the health and safety of operators. This method is becoming increasingly difficult to accept in industry.

Sulfur powder oil content test (desktop nuclear magnetic resonance analyzer)Basic principle:

Using spin echo sequence for measurement, Figure 1 shows the spin echo sequence and the detected nuclear magnetic signal. The free induction decay (FID) NMR signal was measured at t1 after a 90 degree RF pulse. At this point, the signal amplitude (A1) is directly proportional to the number of H protons in the two liquid phases (water and oil) of the sample. After a 180 degree pulse, the amplitude of the spin echo signal is detected to be A2. At this point, the signal of water has already decayed to 0, and A2 is only the signal of oil. Therefore, the difference in amplitude between the two signals A1-A2 is directly proportional to the moisture content of the sample.

After calibration using samples with known moisture and oil content, unknown samples can be tested within 30 seconds to 3 minutes. The testing process is fast and non-destructive, enabling industrial online process testing.

Furthermore, compared to chemical methods,Sulfur powder oil content test (desktop nuclear magnetic resonance analyzer)Nuclear magnetic resonance has better reproducibility, does not require chemical solvents, and can be operated by untrained personnel.

Sulfur powder oil content test (desktop nuclear magnetic resonance analyzer)