Why is step flatness set at ≤0.5 mm?

A: Above 0.5 mm a segment is left loose and 0.6 MPa static pressure seeps there first, so ≤0.5 mm is the precondition for even loading of both gasket rings.

Can the 24% compression rate be raised further?

A: Past 26% the strip takes a permanent set and recovers poorly; below 22% the reserve runs short, and the scrap line is drawn around that window.

Which part is changed first when lid deflection passes 1.2 mm?

A: Retorque the two 390 N latches and check the 14 mm valve insert, then the hinge pin and lid ribs; only when flatness and compression rate both pass is the lid body considered.

Oscilloscope special pressure-resistant waterproof case

Q: Does an IP68 mark mean certification has been granted?

A: The 1.5 m / 40 min immersion and 0.6 MPa / 30 min hold are used here only as benchmark verification of the sealing face on the Oscilloscope special pressure-resistant waterproof case, not as a certificate; acceptance rests on seepage and deflection readings.

Quick answer: The Oscilloscope special pressure-resistant waterproof case is checked at 0.6 MPa for 30 min, with step flatness ≤0.5 mm and gasket compression at 24%.

Case-mouth step flatness of the Oscilloscope special pressure-resistant waterproof case
Gasket recovery under static pressure
Leak reading across immersion levels
Lid deflection points after the static-pressure retest
Compression-rate scrap line for batch air-tightness
FAQ

1. Case-mouth step flatness of the Oscilloscope special pressure-resistant waterproof case

The case-mouth step is the only contact band carrying load once the lid meets the shell. On the Oscilloscope special pressure-resistant waterproof case it is one continuous plane of 520 by 380 by 220 mm outside and 460 by 320 by 160 mm inside. Flatness of ≤0.5 mm is the spread of dial readings around the perimeter, and a lifted segment gives 0.6 MPa static pressure a seam to open first.

The shell is moulded at a 4.0 mm wall with ribs behind the step so the band does not bow as the latches tighten. Flatness is read empty at 4.8 kg and loaded at 10 kg, and the loaded value may not exceed the empty one by 0.1 mm; excess points to mould flash or a skewed latch boss, not a thicker gasket.

2. Gasket recovery under static pressure

Two gasket rings sit in the inner lid groove at a 24% section compression rate. Under 0.6 MPa held for 30 min the lid is pushed inward and the strip squeezed thinner; after release, a strip that does not return to its pre-load reading is scrapped. Poor recovery leaves a hairline gap at the next closing that a static-pressure retest finds first, so the Oscilloscope special pressure-resistant waterproof case reviews recovery before any water test.

Oscilloscope special pressure-resistant waterproof case sand coloured closed shells arranged on a wooden pallet, a wrapped pallet behind and yellow racking on green floor

A 14 mm pressure-valve boss sits at the lid centre, its insert moulded with the lid and its bore rounded so it cannot cut the strip. Two latches on the long sides each deliver 390 N; fit only one, or let the forces drift, and even a ≤0.5 mm step opens at the far end. The working range is -20 to 60 degrees Celsius, with the 24% reserve carrying recovery at the cold end and preventing a permanent set at the hot end. The Oscilloscope special pressure-resistant waterproof case is conditioned at both ends and retested under static pressure.

3. Leak reading across immersion levels

Immersion runs at 1.5 m for a cumulative 40 min, the closed shell held mouth-down, mouth-up and on its side in turn. After opening, absorbent paper pressed to the inner step edge must show no mark. This level is benchmarked against the sustained-immersion condition of IP68 and used only as verification of the sealing face on the Oscilloscope special pressure-resistant waterproof case; lid deflection still needs its own static-pressure retest against the 1.2 mm figure.

Immersion level	Hold time	Reading point
Mouth-down at 1.5 m	cumulative 40 min	lower inner step edge
Mouth-up at 1.5 m	cumulative 40 min	lid groove recovery zone
On side at 1.5 m	cumulative 40 min	latch boss and valve bore

Moisture only at the valve bore means retorque the 14 mm insert and repeat; a mark along a latch boss means the two 390 N latches are out of balance.

4. Lid deflection points after the static-pressure retest

The retest stays on the same shell used for the 0.6 MPa / 30 min hold, with points at the lid diagonal midpoint, the inner latch boss and the valve bore rim. A micrometer reads the lid before and after pressure, and deflection of ≤1.2 mm is accepted. That figure needs both ≤0.5 mm step flatness and the 24% compression rate, which load the gasket evenly and leave the lid room to spring back. All three points on the Oscilloscope special pressure-resistant waterproof case are taken on one shell.

Oscilloscope special pressure-resistant waterproof case red open shell with a gloved worker fitting grey cut base foam, egg-crate lid foam, stacked shells at left

After a 1.0 m drop onto each of the six faces the same points are read again; a value 0.2 mm over the pre-pressure one sends the check to a loosened hinge pin and then to whitening on the lid ribs.

Static-pressure point	Load condition	Allowed deflection
Lid diagonal midpoint	0.6 MPa / 30 min	≤1.2 mm
Inner latch boss	0.6 MPa / 30 min	≤1.2 mm
Valve bore rim	0.6 MPa / 30 min	≤1.2 mm

5. Compression-rate scrap line for batch air-tightness

Before release, three shells per mould cycle are sampled, measuring the real compression rate of the fitted strip; a nominal 24% is accepted only between 22% and 26%, below which the reserve is short and above which the strip is over-compressed. The line is drawn on compression rate alone, because a shell of 520 by 380 by 220 mm outside and 460 by 320 by 160 mm inside drifts little within one mould while the pressed depth shifts with latch force and groove cleanliness. The Oscilloscope special pressure-resistant waterproof case files the shell number against its reading so a later retest traces to a cycle.

Deflection reading	Measuring point	Action
≤1.2 mm	lid diagonal midpoint	accept
1.2 to 1.4 mm	inner latch boss	retorque and retest
over 1.4 mm	valve bore rim	scrap

Filing compression rate, immersion level and static-pressure deflection against one shell number is what makes the air-tightness conclusion on the Oscilloscope special pressure-resistant waterproof case hold, since a dry shell can still ride the 1.2 mm limit under static pressure and is flagged for retest.

Conclusion

The Oscilloscope special pressure-resistant waterproof case links step flatness, the 24% compression of two gasket rings and lid deflection of ≤1.2 mm at 0.6 MPa into one inspection chain. Staying dry at 1.5 m for 40 min is only the entry, while flatness and compression rate govern static-pressure behaviour. Keeping the three tables of immersion levels, static-pressure points and deflection readings per shell locates batch drift better than a single pass mark.