Square Shape Lead Glasses Radiation Shield Panels Size Options 0.2m 0.3m to 2.4m

Practical Q&A for Buyers

Background Note

These Q&As are based on actual installation experience of Jovvi lead glass in radiology and nuclear medicine departments of tertiary hospitals, covering quality, selection, acceptance, and maintenance.

Q1: Can Jovvi lead glass effectively shield PET‑CT (511 keV)?

A: A single 5 mm Pb equivalent Jovvi lead glass panel attenuates 511 keV photons by approximately 50–55% (half‑value layer ~4 mm). Therefore, Jovvi recommends a composite window solution:

• Front layer: 2.5 mm Pb lead glass (physical ~15 mm)

• Middle layer: 10 mm lead acrylic (~3 mm Pb equivalent)

• Rear layer: 2.5 mm Pb lead glass
  Total ~8 mm Pb equivalent, achieving <15% transmission at 511 keV while maintaining acceptable visibility (slight haze but usable).

If the hospital insists on monolithic glass, Jovvi can supply 5.5 mm Pb (physical 32 mm), but weight reaches 130 kg/m², requiring structural wall reinforcement.

Q2: How much Pb equivalent is needed for a SPECT room (140 keV)? How does it differ from CT?

A:

For SPECT applications, Jovvi performs an additional 140 keV grid scan to ensure attenuation variation across the panel is <0.1 mm Pb.

Q3: Will Jovvi lead glass turn yellow (brown) after years of use?

A: Conventional lead glass undergoes browning under long‑term high‑dose X‑ray or gamma irradiation due to hole capture by lead ions and glass network defects.

Jovvi’s nuclear‑grade products include cerium oxide (CeO₂, 0.5–1.2 wt%) as a stabilizer. Third‑party testing shows:

• After cumulative dose of 10⁶ mGy (equivalent to ~50 years of typical SPECT control room exposure), ΔE color change <3.0 – barely noticeable to the naked eye.

• Standard X‑ray grade products (without CeO₂) are not recommended for high‑dose nuclear medicine applications.

Each batch of nuclear‑grade glass includes a radiation stability certificate stating CeO₂ content and test results.

Q4: What is the maximum size? Can custom shapes (rounded corners, holes) be made?

A:

• Maximum monolithic panel: 2000 × 1500 mm (up to 5 mm Pb eq.). For larger sizes, Jovvi offers butt‑joint designs (two panels with staggered overlap, minimal visual impact).

• Custom shapes: Rounded corners (R25–100 mm), cutouts, arched top edges are available. Holes (e.g., for voice ports) must be pre‑ordered – on‑site drilling causes cracks and radiation leakage and is neither recommended nor warranted by Jovvi.

• Tolerances: Dimensions ±1 mm, diagonal difference ≤2 mm.

Q5: How to verify glass quality on‑site? What is the acceptance standard?

A: Jovvi recommends the following three‑step acceptance procedure:

1. Documentation Check

• Factory certificate (Pb equivalent, test method, uncertainty)

• Nuclear medicine supplement (attenuation values at 140 keV and/or 511 keV)

• Visual inspection record (bubbles, scratches, striae)

2. Visual Inspection

• Bubbles: >0.5 mm bubbles ≤1 per 100 cm² (Jovvi internal control <0.5 per 100 cm²)

• Scratches: No visible scratches (minor grinding marks acceptable if they do not obstruct view)

• Striae: No significant flow lines under polarized light

3. Radiation Leakage Test (after installation)

• Use a known‑activity ⁹⁹ᵐTc point source (or X‑ray tube at diagnostic energies)

• Measure dose rate around glass perimeter and at center

• Acceptance criteria: Leakage through glass itself ≤110% of equivalent lead sheet; perimeter gaps sealed with lead tape or gaskets – measured value <0.05 mR/hr (contact)

Q6: Lead glass is heavy. Does the wall need special reinforcement?

A: Yes. Jovvi provides the following guidance:

• For ≤2.5 mm Pb (physical ≤15 mm), weight approx. 50–65 kg/m² – standard light‑gauge steel stud framing with lead sheet can support it.

• For 3.0–5.0 mm Pb (physical 16–28 mm), weight 70–110 kg/m² – requires steel support beam (channel or square tube) beneath the window opening.

• Jovvi can provide installation CAD drawings and weight calculation tables for structural engineer review.

Q7: What certifications and warranty does Jovvi offer?

A:

• Quality management: ISO 13485:2016 (medical devices), ISO 9001:2015

• Product certifications: CE (Class I medical), FDA 510(k) for X‑ray, RoHS compliant

• Warranty period: 5 years (covering radiation‑induced discoloration, spontaneous cracking, measurable attenuation loss)

• Not covered: Impact damage, improper installation (e.g., missing gaskets, over‑tightened bolts), chemical damage from non‑standard cleaners

Q8: What is the lead time and minimum order quantity?

A:

• Standard sizes (≤2.5 mm Pb, up to 1200×800 mm): 25 working days

• Nuclear medicine grade (3.0–5.0 mm Pb, custom shapes): 35–45 working days

• Minimum order quantity: 1 panel (single window purchases supported)

• Packaging: Export wooden crate with desiccant and shock indicators