What matters most for an instrument case in a laboratory?

Answer: Base flatness at 0.3 mm/m, checked after the feet are set. The floor is the reference, so 0.5 mm of warp moves the reading.

What does vehicle transport demand?

Answer: Anchors, slot interference and locked fasteners. At 1.5 g, a case held only by its own weight slides forward.

Which ingress rating does offshore work need?

Answer: IP67 and up, 30 minutes at 1 m, plus a pressure valve; without one, vacuum pushes the opening force past 120 N.

Can one instrument case serve field and workshop?

Answer: The shell can, the insert should not. Field work wants IP67 and a strap; the workshop wants IP54 and a two-hand lift.

Does the insert have to be custom cut?

Answer: For three settings or protruding connectors, yes. For one item in small batches, foam strips work at the cost of uneven grip.

Where an Instrument Case Goes: Scenes and Configurations

Quick answer: An instrument case serves six settings, four of them common: laboratory, vehicle inspection, field survey, offshore platform. The setting decides the insert, the ingress rating, and whether the case is carried by handle or in pairs.

Six Field Settings and What They Share
Laboratory and Metrology Room: Level, Clean, Reach
Vehicle and Field: Vibration, Temperature Swing, Condensation
Offshore and Salt Air: Sealing and Hardware
Trading Off When One Case Covers Several Sites
FAQ

1. Six Field Settings and What They Share

An instrument case ends up in fewer places than a tool box: lab and metrology room, vehicle inspection, field survey, offshore platform, clean line, emergency repair. The kit differs; four demands do not — vibration, level, moisture, and handling.

Rank them by site and the build follows: lab puts level first, vehicle puts vibration first, offshore puts sealing first. Where one case serves two sites, accessories close the gap.

Setting	Site conditions	Structural focus
Laboratory	Bench work, frequent opening	Base flatness, insert grip
Vehicle inspection	Gravel roads, constant shaking	Anchors, fastener locking
Field survey	Long manual carries	Handle and strap paths
Offshore platform	Humid, salty, rolling	Sealing, stainless hardware
Clean line	Wiped down, low dust	Smooth outer surface
Emergency repair	Night work, one hand	Latch opening force

2. Laboratory and Metrology Room: Level, Clean, Reach

On a bench the case sits open all day, so its floor becomes the working surface. Base flatness holds 0.3 mm/m, checked with a level after the four feet are set; 0.5 mm of warp shifts a reading.

Instrument Case: a dark grey case open flat, grey foam lining the lid, squared compartments with two blocks, two latches and a handle

Height follows a 900 mm bench: case under 200 mm tall, lid below eye level so compartments stay visible. Clean lines need a wipeable skin — no texture, no seam, and 50 alcohol wipes without blooming.

A milled EVA block beats foam strips: 2 mm of interference at the cavity walls, 1 mm in bays opened all day.

3. Vehicle and Field: Vibration, Temperature Swing, Condensation

Floor vibration runs 5 to 500 Hz, a gravel road pushes 1.5 g RMS, and 200 km of it backs out fasteners. Strap the case with 25 mm webbing to a floor anchor; weight alone will not hold it under braking.

Four hours at −25 °C, then a room at 25 °C and 85% RH, and water beads outside within two hours. Sealing keeps the inside dry, but moisture swaps as the lid opens, so let it stand indoors.

Field carries pass 500 m, so handle and strap need separate paths: lift points 400 mm apart, 150 mm clear under the base, strap 30 mm above the centre of gravity.

4. Offshore and Salt Air: Sealing and Hardware

Offshore means 90% RH, salt and motion. Seal from IP67, 30 minutes at 1 m, with 316 stainless latches and hinges that show no red rust after 96 hours of salt spray.

Instrument Case: a black hard-shell case closed and tilted above dark water, two latches and a moulded handle facing forward, ripples spreading below

A pressure valve is not optional. A temperature drop pulls a vacuum, and a valved case opens near 60 N where an unvalved one needs 120 N.

Check latch springs and hinge pins every 30 days, rinse white spotting with fresh water, and renew the gasket at 12 months.

5. Trading Off When One Case Covers Several Sites

Buyers want one instrument case for four settings; two or three can often share. Body and seal go to the harshest site, insert to the most frequent, carrying hardware to the farthest, with accessories filling the rest.

Reverse it and both ends suffer: a hard-duty insert slows daily work, a soft-duty shell fails on site. Build the parent case to the hardest setting, then cut one insert per setting.

Setting	Body	Insert	Seal
Laboratory	Flat, levelling feet	Milled EVA	IP54
Vehicle	Mid height, anchor holes	Divided, with trays	IP65
Field survey	Tall, thick corners	Full wrap foam	IP67
Offshore	Low centre, rounded	Barrier bag on tray	IP67

Conclusion

An instrument case earns its place by translating a site into build decisions: level becomes feet and base flatness, vibration becomes straps and slot interference, moisture becomes a rating and a valve, carrying becomes handles and lifting points. Each setting ranks those four its own way, so the shell stays common and the insert carries the difference. A well matched instrument case crosses three sites without changing bodies.

This article discusses only the container (case body) side of specifications and design intent, and does not cover any handling, loading or use of the contents.