Building Electronics for Indian Defence Customers: Environmental Testing, EMC, Documentation and Sourcing, Explained for Product Teams
What does a defence customer buy when it buys an electronics unit? The unit is the smaller part. It buys a file: a specification the unit was designed to, a test plan that was approved before the testing started, a set of reports that prove each requirement was met, a bill of materials that says where every part came from, a record of who inspected what and when, and a promise that the same unit can be built again in three years from the same documents. A commercial IoT team that arrives with a working prototype and a datasheet has built about a third of the deliverable.
This guide is for product teams who build industrial and field electronics for commercial customers and are being asked, for the first time or the fifth, to supply to an Indian defence buyer: a service, a public-sector undertaking, a laboratory, or a prime contractor. It covers the standards that tend to come up, what each one actually tests, how to plan a qualification programme so that it passes the first time, how to design the hardware to survive it, what to document, and what to ask about sourcing before you bid.
A framing note first. This is an engineering orientation, not a contract template. Every defence tender names its own specifications, severities, test authority and inspection stages, and the tender document governs. The standards named below recur often enough to be worth knowing, and the tender wins whenever it disagrees with this post. Where we could not confirm a detail from a primary source, the post says so.
The tender is the specification. Read every referenced standard, issue number and severity level in it before you design anything, and ask the buyer in writing about anything that is ambiguous.
What the Customer Is Really Buying
Defence electronics is bought under conditions commercial teams rarely meet. The equipment lives in vehicles, shelters, ships, aircraft bays and remote posts. Temperatures run from sub-zero highlands to desert heat. The equipment is moved, dropped, shaken on rough roads and shot at by its own platform's vibration. Failure can be expensive in ways a warranty claim does not capture. The buyer manages that risk through process: a documented chain from requirement to design to test to delivery, with named authorities who sign off at each stage.
That is why the file matters as much as the box. When a unit fails in the field in year four, the first questions are about the paperwork: which lot of which component was in that unit, what test did that lot pass, and is the fix applied to every unit built since. A team that can answer from records is trusted with the next order. A team that answers from memory is not.
Three parties usually appear in the picture:
The end user (an army, navy or air force unit, or a defence lab) that writes the requirement.
The quality-assurance authority nominated in the tender, which inspects, witnesses tests and releases the equipment. The 2012 edition of the Joint Services Specification on environmental tests names the authorities by service: a quality assurance organisation for the Army, one for the Navy, and the air force's airworthiness and quality assurance directorate for the Air Force.
The supplier (you, or you under a prime), who owns the design, the test programme and the records.
Knowing who the quality-assurance authority is, and meeting them early, saves months. They tell you which stages they will witness, which labs they accept, and which documents they expect to see before the test, not after.
The Standards That Keep Coming Up
Four families of documents recur in tenders for electronics. The table gives the role of each and the usual mix-up.
Document | What it covers | Where it comes from | The usual mix-up |
JSS 55555 (Joint Services Specification, environmental test methods for electronic and electrical equipment; 2012 revision widely cited) | Environmental tests: climatic (heat, cold, damp heat, salt, dust, rain, fungus), mechanical (vibration, bump, shock) and combined tests | Ministry of Defence, India; stated to be mandatory for defence services' environmental test schedules for such equipment | Assuming it covers EMC. It does not |
MIL-STD-810 (current revision H in many tenders; older G and F still appear) | US military environmental engineering test methods, often referenced alongside or instead of JSS | US Department of Defense | Treating it as a pass/fail list. It is a tailoring document; the tender sets the methods and severities |
MIL-STD-461 (revision G in many tenders) | Electromagnetic emissions and susceptibility requirements (conducted and radiated tests such as RE102, CE102, CS114, RS103) | US Department of Defense | Assuming a commercial EMC report (CE, FCC) satisfies it. It does not |
IS 9000 / IEC 60068 series, JSS 50101, QM-series and customer-specific documents | Basic environmental test procedures and customer or laboratory test methods | Bureau of Indian Standards, IEC, defence standardisation | Overlooking that a tender may call out a mix |
A published description of an Indian standardisation and testing laboratory's environmental capability lists many of these together against each test: cold, dry heat, temperature cycling and shock, damp heat, salt spray, dust, composite temperature and humidity, vibration and bump, with IS 9000, IEC 68-2, JSS 50101, JSS 55555, MIL-STD-202, MIL-STD-810G and similar test-method references named per test. The practical point is that the same physical test often has several valid method references, and the tender says which one you must use.
JSS 55555 is described in the documents we reviewed as covering 31 environmental test methods, and its text states that it is mandatory for preparing environmental test schedules for electronic and electrical equipment used by the defence services, with exceptions for explosives and guided-weapon systems. Its standard testing conditions for measurements are 15 to 35 degrees Celsius, 45 to 75 percent relative humidity and 85 to 106 kilopascals of air pressure. The test-method catalogue includes, among others, dry heat, damp heat, cold, salt spray, dust, drip-proof, rain, bump and vibration tests, and combined temperature, humidity, vibration and altitude tests. Read the edition and revision your tender cites, because the methods and numbers differ across revisions.
A second point from the laboratory side: environmental qualification and electromagnetic compatibility are different test programmes, run in different facilities, and passing one tells you nothing about the other. A procurement specification may require both.
Climatic Requirements: What They Do to a Product
A product team reads a list of test names and sees a calendar. An engineer should read each test as a specific way of killing a design, and know which weakness it hunts.
Test family | What it is trying to break | Typical design weak spot | Design response |
Dry heat and cold soak | Material limits, component ratings, start-up at the extremes | Parts rated commercial (0 to 70 C); electrolytic capacitors at cold; LCDs; battery chemistry | Industrial or military temperature-grade parts; cold-start tests; battery chosen for the range |
Temperature cycling and shock | Solder joints, bonded assemblies, coefficient-of-thermal-expansion mismatches | Large BGAs, ceramic capacitors, connectors soldered to flexible boards | Stiffened boards, underfill, compliant mounts, derated stress |
Damp heat (steady and cyclic) | Corrosion, leakage, insulation breakdown, condensation | High-impedance analogue inputs, unprotected pads, hygroscopic materials | Conformal coating, sealed enclosure, desiccant and breather design |
Salt spray or salt fog | Corrosion of metals, connectors and finishes | Dissimilar-metal contacts, unplated screws, uncoated heatsinks | Corrosion-resistant finishes, gaskets, material choices, drainage |
Dust and sand | Ingress, abrasion, thermal blanketing | Vents, connectors, switches, fans | Sealing ratings, filtered vents, fanless designs |
Rain and drip | Water ingress at seams, glands and windows | Cable entries, seams, breathers | Gland selection, drip loops, gasket compression, test early |
Fungus or mould growth (tropical exposure) | Organic materials supporting growth, with damage to optics and insulation | Natural-material components, some adhesives and plastics | Materials chosen for fungus resistance; coating |
Altitude and low pressure | Corona, outgassing, sealed-cell behaviour, cooling | Sealed capacitors, high-voltage sections, convection-cooled parts | Creepage and clearance margin, pressure-tolerant parts |
Treat the table as a design review checklist before a single chamber is booked. Every row names a failure that is far cheaper to prevent on the drawing board.
Vibration and Shock: The Test That Finds the Loose Part
Mechanical tests are where commercial designs most often meet their first failure. A board that never moved in the lab sees sustained random vibration across a wide band, shock pulses and bump, in three axes. Resonances in heavy components on tall leads, unsupported connectors, large ceramic capacitors on flexible boards, loose screws and wire harness chafing all appear.
A vibration specification usually appears as a power spectral density (PSD) profile: a curve of acceleration energy per hertz against frequency, with a stated overall level in Grms (root-mean-square acceleration) and a test duration per axis. You can compute the Grms from a PSD yourself, which is useful for judging how severe a profile is and for sizing a shaker or a fixture. The calculation integrates the PSD, treating segments on a log-log scale:
# psd_grms.py -- overall Grms from a piecewise log-log PSD (frequency Hz, g^2/Hz)
import math
def grms_from_psd(points):
area = 0.0
for (f1, p1), (f2, p2) in zip(points[:-1], points[1:]):
if p1 == p2:
area += p1 * (f2 - f1) # flat segment
else:
n = math.log(p2 / p1) / math.log(f2 / f1) # slope exponent on log-log axes
area += (p2 * f2 - p1 * f1) / (n + 1) if abs(n + 1) > 1e-9 \
else p1 * f1 * math.log(f2 / f1)
return math.sqrt(area)
print(round(grms_from_psd([(20, 0.04), (2000, 0.04)]), 2)) # flat: 8.91
print(round(grms_from_psd([(10, 0.01), (100, 0.04), (1000, 0.04), (2000, 0.01)]), 2)) # shaped: 7.64
A flat 0.04 g²/Hz profile from 20 to 2,000 Hz works out to about 8.9 Grms. A shaped profile that rolls off at both ends comes to about 7.6. These are illustrative profiles, not anyone's tender, but the calculation is what you use to compare the tender's severity with what your product has seen before.
Design responses that survive the shaker:
Keep mass low and close to the board. A tall, heavy component on long leads is a lever. Choose low-profile parts, or stake and bond heavy ones.
Support connectors and cables. Strain-relieve harnesses, clamp cables at both ends, use locking connectors, and avoid board-edge connectors that carry the cable's weight on solder joints.
Stiffen the assembly. Raise the first resonance of the board assembly above the main energy of the excitation by adding standoffs, ribs or a stiffer mounting. A board that resonates at 150 Hz where the PSD is strongest will amplify the input.
Avoid brittle parts in high-strain areas. Large ceramic capacitors crack when the board flexes. Orient them to reduce strain or use flexible-termination parts.
Lock fasteners. Use thread-locking compounds or locking hardware, and torque specification on drawings.
Test early with a fixture. A single-axis sine sweep on a shaker or even a hand-held impact test reveals resonances before the formal test.
Resonance is the usual killer in a vibration test. Find the first resonance of the assembly early with a sine sweep, and design the mounting so it sits away from the energy in the profile.
Electromagnetic Compatibility: A Separate Programme
MIL-STD-461, in the revision named by the tender, defines requirements and test methods for controlling the electromagnetic interference of subsystems and equipment. Its test names will be familiar to anyone who has read a tender: conducted emissions on power leads, radiated emissions of electric and magnetic fields, conducted susceptibility, and radiated susceptibility. Which ones apply depends on the platform and equipment class, and the tender lists them.
A commercial IoT product starts from a different place. Commercial EMC regimes (CE marking, FCC) test emissions limits designed to protect the radio spectrum and a modest level of immunity designed for homes and offices. Military requirements assume a platform dense with transmitters and radars, a harsh power bus with transients, and the possibility of a close, powerful interferer. Passing the commercial tests does not demonstrate military compliance, and the limits and methods differ in ways that surprise teams.
Practical points for design:
Plan the power input for a platform bus. Military and vehicle buses have wide voltage ranges, surges and transients, and the unit needs input filtering, transient suppression and reverse-polarity protection sized for them.
Think about the radio. A device with a radio transmitter is also a radiator that affects other equipment on the platform. Whether the tender allows an intentional transmitter at all is a question for the buyer, and for some customers the answer is no.
Design the grounding and shielding at the start. Cable shielding, connector shell bonding and enclosure seams matter more than any filter component. A seam with poor contact leaks like a window.
Pre-scan. A near-field probe sweep on the bench, followed by a pre-compliance chamber run, finds the worst problems for a fraction of the cost of a failed formal test.
Conformal Coating, Potting and Sealing: Choose by Failure Mode
Coating and potting are where teams spend money without knowing what they bought. The right choice depends on the risk, the repair policy and the thermal budget.
Option | What it gives | What it costs you | Use when |
No coating, sealed enclosure with breather | Serviceable, cheap | Relies on enclosure integrity | Benign humidity, strong seal, no condensation risk |
Conformal coating (acrylic, silicone, polyurethane or parylene) | Moisture, fungus and contamination protection on the board | Rework is harder; coating can bridge or creep into connectors and keep-out areas; thickness control | Damp, salt-fog or contamination exposure with a need for repair |
Selective coating with masking | Protects what needs protecting; keeps connectors and test points clean | Process cost, masking discipline | Mixed boards with connectors, switches and sensors |
Potting or encapsulation | Strongest protection against moisture, vibration and tampering | Heavy, hard to repair, thermal and stress issues at temperature cycling | Sealed, non-serviceable units with severe shock and vibration or immersion |
Two cautions repeat across projects. A coating applied over flux residue or contamination traps the problem under a film, and boards need cleaning before coating. And rigid encapsulants can stress components through temperature cycling if the thermal expansion mismatch is not managed, so a potted design should be thermally cycled in development, not only in qualification.
Define coating requirements on the drawing: material, thickness range, areas to be masked, cure process and inspection method. The customer's workmanship standards, commonly referenced to IPC documents for acceptance (and the tender will say which class), apply to coating as much as to soldering.
A commercial EMC report (CE or FCC) does not demonstrate MIL-STD-461 compliance. Budget and schedule a separate EMC programme from the first week.
Parts, Derating and the Problem of Time
Component choice is where commercial and defence programmes diverge most, and where the largest hidden costs sit.
Temperature grades. Commercial-grade parts (0 to 70 C) and industrial-grade parts (-40 to 85 C) may not survive the tender's range, and the junction temperature at the hot end is higher than the ambient. Select parts whose rating covers the range with margin, and check the whole bill of materials, including the unglamorous ones: crystals, optocouplers, LCD modules, batteries and connectors.
Derating. Run parts well below their ratings for voltage, current, power and temperature. A derating policy written as a table (for example, capacitors at a fraction of rated voltage, semiconductors at a fraction of rated junction temperature) and reviewed against the schematic gives the customer evidence of reliability design and gives you margin.
Obsolescence. Defence programmes run for years, and components do not last that long. Plan for part end-of-life: choose parts with long supply commitments, keep a list of alternates, qualify second sources, and consider a last-time buy for sole-source parts. A design with no alternates is a design with an end date.
Counterfeit and traceability. Buy from manufacturers and authorised distributors, keep supplier certificates of conformity and lot or date codes, and retain the records. Counterfeit parts enter through spot-market purchases, and a bill of materials that traces every part to an authorised source is both a quality control and a trust document.
Moisture-sensitive and storage requirements. Many parts need controlled storage and baking before assembly. Write the procedure and follow it.
Sourcing deserves a section of its own, but the engineering side is simple: keep a bill of materials column for the manufacturer, the manufacturer's country, the distributor, the grade and the lifecycle status, and keep it current. Defence customers increasingly ask about origin, and the answer costs a morning if the column exists and a month if it does not.
Soldering, Workmanship and the Factory
The acceptability of the soldering and assembly is judged against a workmanship standard, and tenders typically reference the highest class of an industry standard for high-reliability products. IPC-A-610 and J-STD-001 are the usual references for acceptance and soldering requirements, with Class 3 meaning high-reliability products where continued performance is critical; confirm the class and revision the tender calls out. The factory implications:
Trained and certified operators and inspectors for the class required, with training records.
Controlled process: solder paste storage and handling, reflow profile verification, X-ray inspection for BGAs and hidden joints where required, and cleanliness testing.
Lead-free versus tin-lead. Some defence programmes specify or permit tin-lead solder because of whisker risk and long-term reliability concerns, while commercial supply chains have moved to lead-free. If the tender is silent, ask; if it specifies, check the parts' finishes are compatible.
First-article inspection and a documented process for changes. Any change in material, process or supplier after the first article is a configuration change that may need customer approval.
Serialisation. Each unit gets a serial number tied to its build record: lot codes, test results, operators and dates.
Planning the Test Programme So It Passes the First Time
A qualification programme has a shape: an approved test plan, a unit or units of defined configuration (the qualification units, built on the production process), a sequence of tests, witnesses from the authority, and a report. Teams lose months by getting the order wrong.
Get the plan approved before testing starts. The plan lists each test, the method reference, the severity, the pass/fail criteria, the functional checks before, during and after each test, and the sample size. Testing before approval can mean testing again.
Design the functional check. Define a short, fast function test that proves the unit works, and run it before and after every environmental test. Define what "working during the test" means, because some tests require operation and others only recovery.
Sequence to expose weakness early. The tender may fix the sequence. Where it does not, start with the tests that stress what you are least sure of.
Rehearse in-house. Run your own versions of the thermal, vibration and humidity tests with a margin above the specification before the formal run. A rehearsal that finds a failure costs a week. A formal test that finds it costs months.
Book labs early. Accredited environmental and EMC labs have queues, and the authority's witnesses have schedules. Book as soon as the plan is approved.
Keep a configuration record. The units under test are exactly the design that will be delivered, down to firmware version and coating batch.
Environmental Stress Screening and Burn-In
Qualification tests samples; screening tests every unit. Environmental stress screening, usually thermal cycling plus vibration, and burn-in at elevated temperature are used on production units to flush out infant-mortality defects before delivery. Burn-in duration is often justified by an Arrhenius acceleration factor, which converts hours at a stress temperature into equivalent hours at the use temperature. The relation uses an activation energy for the failure mechanism and the temperatures in kelvin:
# burnin.py -- Arrhenius acceleration factor and burn-in hours
import math
K_B = 8.617333e-5 # Boltzmann constant, eV/K
def arrhenius_af(ea_ev: float, t_use_c: float, t_stress_c: float) -> float:
return math.exp(ea_ev / K_B * (1/(t_use_c + 273.15) - 1/(t_stress_c + 273.15)))
def burnin_hours(target_field_hours: float, ea_ev: float, t_use_c: float, t_stress_c: float) -> float:
return target_field_hours / arrhenius_af(ea_ev, t_use_c, t_stress_c)
print(round(arrhenius_af(0.7, 40, 85), 1)) # about 26.0 for Ea = 0.7 eV, 40 C use, 85 C stress
print(round(burnin_hours(1000, 0.7, 40, 85), 1)) # about 38.4 hours to represent 1,000 field hours
With an assumed activation energy of 0.7 electronvolts, burn-in at 85 degrees Celsius accelerates ageing about 26 times relative to 40 degrees, so roughly 38 hours of burn-in represents 1,000 hours of field operation at the cooler temperature. The activation energy is the contentious input, because it depends on the failure mechanism and varies from part to part. Treat the output as a planning figure, document the assumption, and do not claim more than the model supports. Where the tender specifies a screening profile, follow the tender and use the calculation only to understand it.
Write the file as you build the unit. Documents reconstructed from emails after the hardware is done cost more than the hardware did.
The Document Set: Build It as You Go
Teams that write the documents after the hardware is finished spend the last third of the project on paperwork they could have written in the first. A typical set, to be tailored to the tender, looks like this.
Document | Purpose | Written when |
Requirements traceability matrix | Links each tender requirement to design feature, test and evidence | At project start; updated throughout |
Design description and drawings | Defines the product: schematics, layout, mechanical drawings, firmware description | During design |
Bill of materials with origin and lifecycle | Parts, manufacturers, grades, alternates, origins | Maintained continuously |
Reliability and derating analysis | Shows parts used within ratings; may include failure-rate predictions | Before design freeze |
Test plan (qualification and acceptance) | Defines tests, methods, severities, criteria | Before testing; approved by the authority |
Acceptance test procedure (ATP) | The test every delivered unit passes | Before first delivery |
Quality assurance plan | Inspection stages, controls, records, change control | Before production |
Test reports and certificates | Evidence from labs and in-house tests | After each test |
Configuration management record | Hardware and firmware versions per serial number | Ongoing |
User and maintenance manual | Operation, maintenance, spares | Before delivery |
Packing, storage and shelf-life instructions | Handling and storage for the supply chain | Before delivery |
A traceability matrix is the document that most improves a bid and a project. Here is a minimal machine-readable form that can live next to the design files and be checked in CI:
# requirements.yaml -- traceability from tender requirement to evidence
- id: REQ-ENV-004
text: "Operate after dry heat soak at the tender's upper temperature"
source: "Tender clause 4.2, JSS 55555 dry-heat test method (revision per tender)"
design: ["PARTS-GRADE-IND", "THERMAL-ANALYSIS-v3"]
verification: {method: test, plan: TP-ENV-01, report: TR-ENV-01-v2, status: passed}
- id: REQ-EMC-002
text: "Conducted emissions on power leads within MIL-STD-461 limit (revision per tender)"
source: "Tender clause 5.1"
design: ["INPUT-FILTER-v2", "GROUNDING-NOTE-07"]
verification: {method: test, plan: TP-EMC-01, report: TR-EMC-01, status: planned}
- id: REQ-DOC-011
text: "Supply bill of materials with manufacturer and country of origin"
source: "Tender clause 9.3"
verification: {method: inspection, evidence: "BOM-rev-F.csv", status: passed}
A script that fails the build when a requirement has no verification entry or when a "passed" entry has no report makes the matrix live instead of decorative.
A bill of materials with manufacturer, country, grade and lifecycle columns from day one turned a week of archaeology into a morning's export.
Sourcing Questions to Ask Before You Bid
Procurement in defence is shaped by policy as well as by technology, and policy changes. Rather than state rules we could not verify against primary sources for this post, here is the list of questions to put to the buyer and to your own supply chain, in writing, before a price goes out.
Origin and content. Does the tender specify a minimum indigenous content, a list of items that must be sourced domestically, or restrictions on parts and subsystems from particular countries? How is content measured and evidenced?
Indigenisation and listed items. Are any items in the unit on a list of products the buyer will only procure from domestic sources? Does the customer maintain a portal or list for indigenisation, and have you checked it for your key components?
Approved vendors and sources. Must key components, labs or manufacturing sites be on an approved list? Is the manufacturing site subject to audit by the quality-assurance authority?
Security. Are there requirements about firmware provenance, remote connectivity or update mechanisms, data storage, or the origin of radio and processing components? Can the equipment contain a cellular or Wi-Fi radio at all?
Export and end-use controls. Do any components in the product carry export-control conditions that affect re-export or supply to this end user?
Lifecycle commitments. How long must the supplier support the design, supply spares and repair, and what is the obsolescence-management expectation?
Intellectual property and data rights. Who owns the design, and will the buyer expect to receive source or manufacturing data?
Treat the answers as part of the bill of materials. A product designed around a sole-source part from a restricted origin is a product that cannot be delivered, however good it is.
A Condition-Monitoring Node's First Qualification
A representative composite, genericised, shows how the pieces interact. A commercial IoT team adapted a battery-and-mains vibration monitoring node for a defence maintenance workshop. The unit sat in a rugged aluminium enclosure, ran from the workshop's power supply, and sent readings over a low-power radio to a gateway. The team's commercial design had passed its own tests, and the buyer's tender called for environmental and EMC qualification, a document set, and a bill of materials with origins.
The first plan, built by engineering, budgeted six weeks for testing. The first rehearsal changed that. On the shaker, a tall electrolytic capacitor on long leads rang at a resonance near the strongest part of the profile and cracked a solder joint within minutes. In damp heat, an unprotected high-impedance sensor input developed leakage that shifted the reading by several percent. A conformal coating added to fix the second problem crept into a pin header and caused an intermittent connection. In EMC pre-scan, the switching power stage radiated above a limit at a frequency the commercial test had never covered, and the connector shell had a poor bond to the enclosure.
The fixes were ordinary engineering. The capacitor was replaced with a low-profile part and staked. The sensor input was redesigned with guard traces, and the board was selectively coated with the header masked. The power stage got a filter and a layout change, and the connector shell was bonded with a conductive gasket. Each fix was tested with a quick in-house version of the failing test before the next rehearsal, and the formal qualification passed with one retest of an EMC scan rather than the multiple retests the first plan would have needed.
The documents took longer than the hardware. A traceability matrix started late had to be reconstructed from emails. The bill of materials had no origin column, and filling it for 300 line items took two people the better part of a week. The team's change to the process after the project is the one this post recommends: the requirements file and the bill-of-materials columns exist from day one. The schedule figures behind this account are illustrative of the pattern. The pattern is that tests find mechanical and EMC problems that functional prototypes hide, and that late paperwork costs more than early.
When to Walk Away From a Defence Bid
The tender cannot be read. If the requirement documents are not available, are ambiguous, or the buyer will not clarify, the risk is unpriceable.
Sourcing constraints cannot be met. A required domestic content or restricted-origin rule that your design cannot satisfy without a redesign is a different project.
The volumes do not support the qualification cost. Qualification can cost more than a small order is worth. Calculate it before bidding, and consider whether the qualification can be reused for follow-on orders.
The team lacks a quality system. If you cannot trace a part to a lot, control a process change or keep records, the first audit will fail.
A radio or cloud connection is core to your product and prohibited by the customer. Check this first, as it changes the architecture.
You cannot support the product for the life the buyer expects. A ten-year support commitment from a design with unmanaged obsolescence is a promise you will break.
Starting on Monday
Obtain and read the tender and every referenced standard, with the revision and severities. List ambiguities and send them to the buyer in writing.
Identify the quality-assurance authority and request a meeting, before design freeze.
Start the traceability matrix and the bill-of-materials columns today: manufacturer, country, distributor, grade, alternates, lifecycle status.
Run a design review against the climatic and mechanical tables in this guide: parts grades, resonances, connectors, coating, sealing, grounding.
Build a rehearsal plan: in-house thermal, damp-heat, vibration and EMC pre-scans with margin above the specification, before any formal lab is booked.
Write the test plan, the ATP and the quality plan and send them for approval.
Compute the screening and vibration numbers with the scripts, and record the assumptions.
Price the whole programme: qualification, documents, screening, spares, support, obsolescence management. Bid on the total, not on the build cost.
The File Outlasts the Unit
A defence electronics unit will be bolted into a vehicle, shaken, heated, rained on and forgotten for years. When someone eventually opens the file to ask what that unit was, how it was tested and what was in it, the quality of the answer decides whether the next order comes. Build the hardware to survive the chambers, and build the file so that it can answer for the hardware long after the team that wrote it has moved on.
EurthTech is an engineering-first product design and embedded systems company with a development center in Hyderabad. To discuss a project, write to connect@eurthtech.com or see https://www.eurthtech.com/case-studies.
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