CENTRIFUGAL TUBE WITH STAND – FULL DESCRIPTION

A Centrifugal Tube with Stand (also known as a Settling Tube or ASTM Centrifuge Tube) is a calibrated, transparent measuring tube used in Magnetic Particle Inspection (MPI) to determine the concentration of magnetic particles in the suspension (bath).
It is an essential tool for bath concentration control as required by ASTM E1444, ISO 9934, and major MPI standards.

The stand holds the tube upright and steady during settling.

---

✔ Purpose of the Centrifugal Tube

It is used to:

• Measure particle concentration in MPI bath

• Check for bath contamination (oil, water, rust, sludge)

• Ensure correct particle-to-carrier ratio

• Maintain consistent inspection sensitivity

• Verify bath health daily

It ensures the MPI system is working within acceptable limits.

---

✔ Construction

A typical Centrifugal Tube with Stand includes:

1. Centrifugal Tube

• Material: Clear glass or high-grade acrylic

• Capacity: 100 mL (most common)

• Graduations:

  • 0–1.5 mL (sensitivity range)

  • Marked every 0.05 mL for precision

• Shape: Thin cylindrical tube with pointed bottom

• Calibrated for accurate measurement

2. Tube Stand

• Usually metal or plastic

• Holds the tube vertically

• Ensures zero vibration during settling

• May include tube clamp to prevent movement

---

✔ Working Principle

1. Magnetic particles suspended in the carrier fluid (oil/water) are poured into the tube.

2. The tube is left undisturbed for 30 minutes (standard settling time).

3. Magnetic particles settle at the bottom of the tube.

4. The height/volume of the settled particles indicates:

   • Correct concentration

   • Over-concentration (too many particles)

   • Under-concentration (too few particles)

   • Contamination in the bath

---

✔ Typical MPI Bath Acceptance Limits

Also identifies contamination:

• Brown/yellow layer = oil contamination

• Cloudy layer = water contamination

• Muddy layer = rust/sludge

---

✔ How to Use the Centrifugal Tube (Step-by-Step)

1. Shake the MPI bath thoroughly (agitation).

2. Fill the tube to the 100 mL mark.

3. Place the tube in the stand, perfectly vertical.

4. Let it settle for 30 minutes undisturbed.

5. Read the volume of settled particles at the bottom.

6. Compare with acceptance limits.

7. Drain and clean the tube immediately after use.

---

✔ Applications

Used for MPI bath testing in:

• MPI bench units

• Field water/oil bath checks

• Fluorescent and visible MPI systems

• Bath contamination analysis

• Quality control in NDT labs

---

✔ Advantages

• Highly accurate concentration measurements

• Simple to use

• Provides quantitative results

• Required by major MPI standards

• Detects bath contamination

---

✔ Limitations

• Must be handled carefully (glass)

• Requires 30 minutes settling time

• Needs proper cleaning to avoid false readings

• Should be stored upright to protect calibration

---

If you want, I can also provide:

📌 ALT image description of Centrifugal Tube with Stand
📌 Short catalog description
📌 Bath concentration calculation sheet
📌 Daily bath control checklist for MPI

Just tell me!