PS7500 Na22 Exempt-Activity vs Berthold LB7440 Cs137 Radiometric Density Meter
PS7500 uses Na22 exempt-activity source (< 1000 KBq); Berthold LB7440 uses high-activity Cs137 (typically 37~370 MBq). This table compares measurement performance, compliance burden, operating cost.
Feature comparison
| Feature | Na22 density meter | Berthold LB 7440 / LB 414 |
|---|---|---|
| Measurement principle | γ-ray transmission (Na22 exempt) | γ-ray transmission (Cs137 high-activity) |
| Source activity | < 27 μCi / < 1000 KBq | 1~10 mCi / 37~370 MBq |
| Activity ratio | 1/1000 ~ 1/10000 of Cs137 | Baseline |
| Half-life | Na22: 2.6019 years | Cs137: 30.07 years |
| Leakage dose | ≤ 0.1 μSv/h | Requires shielding calc (≤ 2.5 μSv/h work zone) |
| Radiation use license | NOT required (within exempt activity) | Required (use + transport + decommissioning) |
| Radiation operator cert | NOT required | Required (training + certification) |
| Density range | 0~3 g/cm³ | 0~3 g/cm³ |
| Density accuracy | ±0.002 g/cm³ | ±0.001 g/cm³ (high-activity config) |
| Process temperature | ≤ +200°C | ≤ +400°C (high-temp config) |
| Pipe size range | DN50~DN1000 | DN50~DN1500 |
| Transport / decommission | Normal equipment, no radiation restrictions | Radiation transport vehicle + disposal permit |
| Lead time | 6~10 weeks | 12~20 weeks (incl. license approval) |
Competitor parameters cited from Berthold LB 7440 / LB 414 datasheet.
Takeaway
Berthold is the global technical leader in radiometric density meters, with the LB family widely deployed in heavy-media coal washing, smelting, oil & gas, and other extreme applications. PS7500 uses the same gamma-transmission principle but with Na22 exempt-activity source (1/1000 to 1/10000 the Cs137 activity), completely avoiding radioactive-source licenses, transport permits, and operator certifications. At comparable accuracy and durability tier, PS7500's compliance and operating burden are substantially lower — the preferred choice for most projects. Only extreme applications (activity requirements beyond the Na22 range) still need traditional Cs137.