How does a biological sample/specimen sealed transit box differ from a plain protective case?

Answer: Absorbent capacity and pressure differential. A plain case covers IP67 ingress only; this body carries 400 mL and holds 95 kPa for 30 min.

How is the 95 kPa differential tested?

Answer: The closed case sits in a pressure chamber at 95 kPa for 30 min; a dry inner wall passes.

Is 400 mL of absorbent enough?

Answer: That is the floor capacity of this biological sample/specimen sealed transit box; whether it suffices depends on the pack and how it is stood.

Is the 4 °C / 8 h figure validated?

Answer: No. Eight hours with 2 gel packs is a configuration statement; validation needs probes, a curve and a maximum deviation.

Can IP67 replace the 95 kPa test?

Answer: No. IP67 is 30 min at 1 m from outside, 95 kPa is a differential across the shell, so both tests stand.

Biological sample/specimen sealed transit box

Quick answer: A biological sample/specimen sealed transit box is the outer layer: 400 × 300 × 180 mm, 400 mL absorbent, 95 kPa for 30 min, 2 latches at 300 N.

The outer layer, and only the outer layer
Fitting 400 mL of absorbent into a 340 × 240 mm floor
95 kPa differential and IP67 are two different loads
After a 1.2 m drop, inspect the latch seats first
Three label positions and the 4 °C / 8 h boundary
FAQ

1. The outer layer, and only the outer layer

Three layers, three jobs: the innermost sits against the specimen, the middle takes up an accidental leak, the outer absorbs crush, drops and rain. A biological sample/specimen sealed transit box is that third layer; it holds the other two in place rather than sealing for them.

The shell measures 400 × 300 × 180 mm outside, 340 × 240 × 140 mm inside, 3.0 mm wall, 3.4 kg empty. The gap between the footprints is not slack: 30 mm each side carries the absorbent pad, 20 mm top and bottom carries ribs and the closing face.

Table 1: What the outer layer must do

Packing layer	Duty	Requirement
Outer, shell	Crush, drop, rain	3.0 mm, 400 × 300 × 180 mm
Outer, absorbent	Hold a leak on the floor	400 mL over 340 × 240 mm
Outer, closing face	Hold the pressure difference	95 kPa for 30 min
Outer, latches	Keep the gasket compressed	2 at 300 N each

Of the 3.4 kg empty weight, 0.6 kg sits in seats and ribs; a carrier rarely walks more than 800 m with one in hand.

2. Fitting 400 mL of absorbent into a 340 × 240 mm floor

The floor of the biological sample/specimen sealed transit box is 340 × 240 mm, or 81,600 mm², so 400 mL is a 4.9 mm layer of liquid; a pad holding eight times its volume needs about 12 mm of thickness, with a 30 mm upturn over the wall joint.

Biological sample/specimen sealed transit box showroom shelving wall, blue, orange, yellow and black cases on white boards, several lids open

Fixing decides whether the pad survives a 1.2 m side drop: four dots of tape or a 1 mm PP plate keep the corners covered, while a loose pad slides to one end and halves capacity. A 5 mm air gap then drains condensate down a 1° slope.

3. 95 kPa differential and IP67 are two different loads

The 95 kPa test asks whether shell and closing face stay leak-free when inside and outside differ by 95 kPa, which maps onto a hold pressure change stacked with ground handling. IP67 asks whether water enters in 30 min at 1 m of still water; load direction, medium and criterion all differ, so swapping one for the other is the commonest misreading.

The weak point under 95 kPa on a biological sample/specimen sealed transit box is the middle of the largest panel. With a 3.0 mm wall and ribs at 120 mm centres, the centre of a 400 × 300 mm lid moves about 1.8 mm, so the gasket needs squeeze in reserve or the differential escapes through the joint.

Table 2: Closing face and seal values

Seal element	Value	Criterion
Gasket section	6 mm	EPDM sponge, 55 Shore C
Groove depth	4.5 mm	25% compression, 1.5 mm
Latch hold	2 at 300 N	Never under 15% compression
Lid ribbing	120 mm centres	≤ 2 mm at 95 kPa

A quarter is the usual band for EPDM sponge: under 15% rebound is weak, over 40% the strip takes a set in six months. The latches at 300 N hold that compression but do not carry the differential.

4. After a 1.2 m drop, inspect the latch seats first

A biological sample/specimen sealed transit box is dropped from 1.2 m onto six faces and three edges, opening the lid after each impact. No latch may release, no gap may open, and the 340 × 240 × 140 mm cavity must not shift by more than 2 mm.

Biological sample/specimen sealed transit box, three black cases open on a shelf, orange foam with die-cut cavities and a grey printed panel inside

Release starts at the seat root, not the latch body. On a corner drop the moment of an ABS seat concentrates between its two M4 holes, and at 22 mm spacing root stress peaks; holes at 30 mm with a 1.5 mm fillet keep it intact.

The shell rarely fails at this height, flatness of the closing face does. A 1 mm dent leaves one stretch of gasket under 25% compression and the pressure test bubbles there first, so the order is seat, joint, flatness. Impact copolymer PP, PA66 with 30% glass and EPDM cover the −20 °C to 55 °C range.

5. Three label positions and the 4 °C / 8 h boundary

A biological sample/specimen sealed transit box carries three labels: top left of the lid face, 30 mm beside the right latch, bottom right of the floor. Three faces mean the same data reads within a second whichever way the case is stood.

An 80 × 50 mm PVC label goes on the lid, a 40 × 20 mm label of the same stock at the latch, and an in-mould label formed with the shell on the floor; the adhesive ones face 50 wipes of 75% alcohol.

For this biological sample/specimen sealed transit box, 4 °C for 8 h with 2 gel packs is a configuration statement, not a validation. The cavity is 11.4 L and two 500 g packs take about 1.0 L, leaving air volume and heat leak to shape the curve.

Table 3: The three label positions

Position	Format	Size and criterion
Lid face, top left	PVC adhesive	80 × 50 mm, 15 mm from edge
Beside right latch	PVC adhesive	40 × 20 mm, 30 mm from latch
Floor, bottom right	In-mould label	Formed with shell, 24 h at −20 °C

Conclusion

The value of a biological sample/specimen sealed transit box is what a 400 × 300 × 180 mm footprint pins down: 400 mL of absorbent that spreads, a face that stays shut at 95 kPa, and two latches still seated after a 1.2 m drop. The 3.0 mm wall and 25% gasket compression are the base; three label positions make a batch read as one product.