Sand core filter funnel measuring aperture verification device

1、 Product Overview

The sand core filter funnel pore size calibration device is a specialized calibration equipment independently developed by our company to strictly implement the technical requirements of Appendix A of JJG (Transportation) 189-2023 "Verification Regulations for Asphalt Wax Content Measuring Instruments". Mainly used to accurately determine whether the pore size of the sand core filter funnel used in the asphalt wax content test meets the standard.

The calibration device for measuring the aperture of the sand core filter funnel adopts the principle of positive pressure bubble method. Through a precision pressure control system and a high-definition visual observation system, it achieves objective, accurate, and traceable measurement of the maximum aperture of the sand core funnel, changing the drawbacks of relying on subjective judgment in traditional methods. It is an ideal tool for various levels of metrological verification institutions, asphalt laboratories, and product quality control departments.

2、 Core working principle

The device applies a steadily increasing gas pressure to the interior of the sand core funnel immersed in liquid through a gas source. When the pressure value overcomes the liquid surface tension of the capillary tube with the maximum aperture of the sand core funnel, the first bubble will be generated at that location. At this point, the pressure value recorded by the precision pressure gauge is the critical pressure, and the equivalent aperture of the sand core funnel can be obtained through formula conversion.

System composition and functional characteristics

1. Stable fixing device

• Using specialized fixtures, different specifications of sand core filter funnels can be stably fixed to ensure good sealing and no displacement during the pressurization process.

• The integrated fixed gas flow control valve and pressure measurement interface have a compact structure and easy operation.

2. Precision pneumatic control system

• Gas source interface: It can be connected to a manual pressure pump or a fully automatic pressure calibrator, providing a stable and reliable pressure source.

• Gas flow control valve: It can fine tune the intake flow rate to ensure that the pressure can increase steadily and slowly, avoid pressure shock, and ensure the accuracy of measurement results.

• Pressure measurement standard interface: Provides a standard universal interface that can be connected to 0.4 level precision pointer pressure gauges or higher precision (such as 0.05 level) digital pressure gauges to meet the needs of different levels of calibration.

3. Innovative sealing and pressure measurement design

• The top of the device is designed with a dedicated rubber sealing joint that matches the grinding mouth of the sand core funnel. One end of the connector is tightly connected to the funnel, and the other end is connected to the pressure gauge.

• Key advantage: This design ensures high sealing of the entire pressurization and pressure measurement circuit (from the pressure pump to the pressure gauge itself), without any air leakage. The final pressure will only act on the sand core funnel. When the pressure reaches the critical value, gas escapes from the aperture of the tested sand core funnel to produce bubbles, thereby accurately locking the leak point and obtaining reliable data.

4. High definition visual observation system

• Equipped with a high-definition camera, it can accurately aim at the bottom of the sand core funnel.

• By directly connecting to a computer through a data cable and using dedicated software, the bubble generation status on the surface of the sand core can be synchronously and clearly observed on the computer screen.

• The software supports functions such as image enlargement, recording, and screenshot saving, providing intuitive visual evidence for the verification process and achieving visualization and traceability of the detection process.

5. pressure outlet

• Used to connect the suction bottle below and hold the immersion solution (usually anhydrous ethanol or isopropanol), so that the sand core funnel can be immersed in the liquid, providing necessary conditions for bubble method testing.

Application scenarios

• Metrology Institute: Mandatory calibration of sand core funnel in asphalt wax content measuring instrument.

• Highway Engineering Laboratory: Conduct periodic verification and quality monitoring of sand core funnels used in daily operations.

• Quality control and research and development of asphalt and asphalt mixture production.