Temperature & Humidity Chamber for Electronics: IEC 60068 Guide | Indeecon

Moisture and temperature are the two stresses that kill electronics quietly. A PCB doesn't usually fail on the bench — it fails eighteen months later in a humid coastal warehouse, or after a few thousand day-night cycles on an outdoor installation. A temperature and humidity chamber lets you find those failures in weeks instead of years, and IEC 60068 is the standard framework that tells you how to run the tests so the results mean something.

We build these chambers for electronics manufacturers, so this guide is practical: which IEC 60068 tests apply to electronics, what conditions to run, and how to make sure the chamber you buy can actually deliver them.

Why electronics need combined temperature and humidity testing

Temperature alone and humidity alone each cause damage, but the combination is what mirrors real life and does the most revealing harm:

• of tracks, pads, and connectors.
• and reduced surface resistance, causing leakage.
• into components and potting.
• during temperature transitions, which shorts and corrodes.
• between closely spaced conductors under bias.

A temperature and humidity chamber reproduces these conditions under control. Our chambers hold −70 °C to +180 °C and 20% to 95% RH with a PLC-based touchscreen controller and graphing, which covers the full spread of IEC 60068 climatic tests for electronics.

The IEC 60068 tests that matter for electronics

IEC 60068 is a family of environmental test methods, not a single test. These are the ones electronics teams use most:

Cold — IEC 60068-2-1

Confirms the product operates and survives at low temperature. Relevant for outdoor, automotive, telecom, and cold-storage electronics. Batteries and displays are common weak points.

Dry heat — IEC 60068-2-2

Elevated temperature exposure to expose material degradation, solder and adhesive weakening, and electrical drift. Semiconductors, plastics, and control devices are typical subjects.

Damp heat, cyclic — IEC 60068-2-30

One of the most important tests for electronics. The chamber cycles temperature up and down at high humidity, deliberately driving condensation and "breathing" of moisture into enclosures. This is where corrosion, insulation failure, and moisture ingress reveal themselves. It's run in a damp heat test chamber.

Damp heat, steady state — IEC 60068-2-78

Sustained high temperature and humidity (for example 40 °C / 93% RH) held constant for long durations to assess long-term moisture effects and surface leakage.

Change of temperature — IEC 60068-2-14

Repeated transitions between hot and cold to stress solder joints, seals, and material interfaces through expansion mismatch. For very rapid transitions, a dedicated thermal shock chamber with sub-10-second transfer is used instead of a standard climatic chamber.

Typical setpoints and durations

Your product specification or customer will define exact conditions, but common electronics profiles include:

Run the device powered and monitored where the standard allows — many humidity-driven failures only appear under electrical bias.

Tell us your standard, setpoints, and product size and we'll spec a temperature-humidity or damp heat chamber that runs the exact profiles you need. Request a quote or talk to an applications engineer.

How to spec the right chamber for electronics testing

The chamber has to hit your conditions reliably and hold them evenly around the product. Look at:

• — must cover your worst-case setpoints with margin. A chamber that only just reaches 95% RH will struggle to hold it steadily.
• — tight, documented spread across the working volume, so every unit under test sees the same conditions.
• — proper humidification and dehumidification for stable RH, especially in cyclic damp heat where the chamber must actively drive condensation and then recover.
• — to run multi-segment IEC 60068 profiles and produce traceable records for compliance.
• — for powering and monitoring the DUT (cabling, sensors) without breaking the seal.
• — adequate ramp rates for -2-14 change tests; move to a thermal shock chamber for very rapid transitions.

Where this fits in a full electronics test plan

Climatic testing is one axis. A complete reliability programme usually pairs it with corrosion (salt spray or cyclic corrosion), ingress protection (dust and water), and mechanical (vibration/shock). We help electronics manufacturers build out chambers across that plan, and offer rental chambers for one-off qualification campaigns and AMC support to keep chambers in calibration.

Frequently asked questions

Which IEC 60068 test is most important for electronics?

Damp heat cyclic (IEC 60068-2-30) is often the most revealing, because the temperature cycling at high humidity drives condensation and moisture ingress — the mechanisms behind most field failures in electronics. Damp heat steady state (2-78) complements it for long-term effects.

What temperature and humidity range do I need for electronics testing?

It depends on your product's environment, but a chamber covering roughly −40 °C to +85 °C and up to about 95% RH handles the common IEC 60068 climatic profiles. Chambers like ours span −70 °C to +180 °C and 20–95% RH for wider coverage.

Should electronics be powered during humidity testing?

Where the standard permits, yes. Many humidity-driven failures (leakage, electrochemical migration, dendrites) only occur under electrical bias, so powered, monitored testing catches failures that unpowered testing misses. This requires chamber access ports for cabling.

What's the difference between damp heat cyclic and steady state?

Cyclic (2-30) varies temperature at high humidity to force condensation and "breathing", stressing ingress and corrosion. Steady state (2-78) holds constant temperature and humidity for long periods to assess sustained moisture effects and surface leakage.

Do I need a separate thermal shock chamber?

If your temperature-change test requires very rapid transitions (seconds), yes — a dedicated thermal shock chamber transfers samples between hot and cold zones far faster than a single climatic chamber can ramp. For slower change-of-temperature tests (2-14), a good temperature-humidity chamber is sufficient.

Share your IEC 60068 profiles and product dimensions and we'll recommend a temperature-humidity or damp heat chamber with the right controller and ports. Request a quote · Call or WhatsApp our team.

Salt Spray vs Cyclic Corrosion Chamber: Which Do You Need?

If corrosion testing is on your roadmap, you'll hit this decision quickly: a standard salt spray chamber, or a cyclic corrosion chamber? They look similar, they both accelerate corrosion, and one costs noticeably more than the other. Buying the wrong one means either paying for capability you'll never use, or discovering mid-project that your chamber can't run the protocol a customer specified.

This is a buying decision, so we'll treat it like one. (If you want the deeper argument about how well *any* lab corrosion test predicts real-world life, see our companion article on salt spray accuracy — this piece is about which chamber to put on your purchase order.)

The short answer

Buy a if your requirement is continuous salt-fog exposure to ASTM B117 or ISO 9227 — quality control of coatings and plating, supplier qualification, and comparative screening. Buy if your customers or standards demand alternating wet, dry, and humidity phases that correlate better with real service — common in automotive and increasingly in general manufacturing.

What a salt spray chamber does

A standard salt spray chamber continuously atomises a sodium chloride solution into a fine, temperature-controlled fog. Parts sit in that constant saline mist for a defined period — hours to thousands of hours — and you assess when and how corrosion appears.

Its defining trait is : continuous fog, fixed temperature, no drying. That constancy is exactly what makes it repeatable and comparable across labs, which is why it has been an industry staple for decades. It's governed mainly by:

• — the classic continuous neutral salt spray practice.
• — neutral salt spray (NSS), acetic acid (AASS), and copper-accelerated (CASS) variants.

Salt spray chambers excel at process control (is the plating thickness and coating consistent batch to batch?), defect detection (porosity, poor adhesion), and ranking similar coatings under identical conditions.

What a cyclic corrosion chamber does

A cyclic corrosion chamber does everything a salt spray chamber does, then adds programmable phases: salt fog, then a dry-off, then controlled humidity, sometimes ambient rest — repeated in cycles. This wet-dry-humid cycling mimics what a part actually experiences outdoors far more closely than constant fog.

Because real corrosion is driven by wetting and drying, not permanent saturation, cyclic testing (CCT) tends to produce corrosion morphology and relative rankings that correlate better with field observations.: That's why automotive OEMs increasingly specify cyclic protocols (such as those in the ISO 11997 or various OEM standards families) rather than plain B117.

The trade-off: a cyclic chamber is more complex, more capable, and more expensive. It's a superset of salt spray capability.

Side-by-side comparison

How to decide — a practical checklist

Work through these in order:

1. If a customer names a cyclic protocol, that decides it — a plain salt spray chamber can't run it. If they name B117 or ISO 9227 NSS, a salt spray chamber is sufficient.
2. Internal QC and coating comparison → salt spray is fine. Product life claims and automotive supply → lean cyclic.
3. Electroplating/galvanising process control → salt spray. Complex assemblies, painted body panels, fasteners expected to survive years outdoors → cyclic.
4. If cyclic requirements are likely within a few years, buying cyclic now avoids a second purchase.A cyclic chamber also runs straight salt spray when you need it.
5. If budget is tight and today's need is genuinely B117 QC, a salt spray chamber is the right, honest choice.

Send us the corrosion standards your customers require and the parts you're testing — we'll recommend a salt spray or cyclic corrosion chamber sized for your samples. Request a quote or talk to an applications engineer.

Don't overlook these when buying either chamber

• — size for your largest part and realistic batch, plus airflow around samples.
• — B117 and ISO 9227 specify collection rates; the chamber must hold them evenly.
• — the chamber runs in the exact conditions designed to corrode things.Build quality matters here more than almost anywhere.
• — reservoir, saturation tower, and stable heating.
• — a genuinely flexible recipe engine so you can match any OEM cycle.
• — for traceable, auditable records.

Our chambers are built with industrial-grade, corrosion-resistant construction and custom capacities and sample racks. Where corrosion is one part of a broader durability programme, teams often pair these with a temperature and humidity chamber for combined climatic testing. If you only need corrosion capacity for a single project, ask about rental.

Frequently asked questions

Is a cyclic corrosion chamber better than a salt spray chamber?

Not universally — it depends on your requirement. Cyclic chambers correlate better with real-world corrosion and are needed for many automotive protocols, but salt spray chambers are simpler, cheaper, and perfectly suited to ASTM B117 / ISO 9227 quality control and coating comparison. A cyclic chamber can also run plain salt spray.

Can a salt spray chamber run cyclic corrosion tests?

No.A standard salt spray chamber only produces continuous salt fog. Cyclic protocols require programmable dry and humidity phases, which need a cyclic corrosion chamber.

What standards apply to salt spray testing?

The most common are ASTM B117 (continuous neutral salt spray) and ISO 9227, which includes neutral salt spray (NSS), acetic acid salt spray (AASS), and copper-accelerated acetic acid salt spray (CASS).

Does passing salt spray guarantee real-world durability?

No. Salt spray is excellent for comparison and process control but does not directly predict field life, because it lacks the wet-dry cycling of real environments. Cyclic corrosion testing correlates better, which is why it's often specified for life-relevant claims.

How do I size a corrosion chamber?

Base it on your largest sample and a realistic batch, allowing space for even fog distribution and airflow around parts. Undersized chambers force overcrowding, which skews results.

Share your standards, samples, and batch size — we'll recommend a salt spray or cyclic corrosion chamber and rack layout to fit. Request a quote · Call or WhatsApp our team.

Environmental Stress Screening (ESS) Testing: A Complete Guide

What is Environmental Stress Screening (ESS)?

Environmental Stress Screening (ESS) is a 100% production screen applied to electronic hardware to precipitate and detect latent defects — faults that are present in a product but have not yet caused failure under normal conditions. By applying controlled environmental stresses during manufacturing, ESS shifts early-life failures from the field (where they are expensive and damaging) to the factory floor (where they are cheap to detect and fix).

ESS is widely used in defence electronics, aerospace avionics, industrial control systems, telecommunications equipment, and increasingly in automotive electronics. It is specified in standards including MIL-HDBK-2164A and IEC 60068 test methods.

Why is ESS Important?

Electronic assemblies contain components and solder joints that may have marginal workmanship defects — cold solder joints, marginal component tolerances, hairline fractures, or contamination — that are not detectable by standard inspection or electrical test at room temperature. These defects only manifest as failures after some period of operation, often within the first few hundred hours — the 'infant mortality' or 'burn-in' period.

This early failure period is the steep portion of the 'bathtub curve' of reliability. ESS compresses this early-failure period into the factory, where failures are cheap to detect and fix — rather than in the field, where warranty costs, safety incidents, and reputational damage follow.

How Does ESS Work?

ESS typically involves two primary stress inputs applied to the product simultaneously or sequentially:

1. Temperature Cycling

The product is cycled between low and high temperature extremes — typically −40°C to +70°C or similar — at defined ramp rates (often 5–20°C/min). The thermal expansion and contraction stresses applied to solder joints and component leads are highly effective at precipitating marginal workmanship defects. The number of cycles and temperature range are defined by the ESS profile, which is derived from the product's reliability requirements and design margins.

2. Vibration (Random Vibration)

The product is mounted on a vibration table and subjected to broadband random vibration across a defined frequency spectrum (typically 20 Hz to 2,000 Hz). Vibration effectively screens for loose hardware, marginal solder joints, and connector issues that thermal cycling alone may not detect.

Combined temperature and vibration screening — where both stresses are applied simultaneously — is the most effective form of ESS and is required for many military and aerospace applications.

ESS vs HALT: What's the Difference?

• HALT is used during product development to find design weaknesses. It uses extreme stresses well beyond the product's specification limits to quickly find failure modes.
• ESS is a production screen applied to every unit (100% screen). It uses moderate stresses within the product's operating margins to detect manufacturing defects without consuming significant product life.
• HASS (Highly Accelerated Stress Screen) is a production screen that uses higher stress levels than traditional ESS — derived from HALT data — to provide a more efficient screen with fewer cycles.

In practice, a product development programme will typically use HALT to define the stress limits, then design an ESS or HASS profile for production based on those limits.

What Equipment is Used for ESS?

ESS requires environmental test chambers capable of fast temperature ramp rates and, optionally, combined vibration capability:

• Temperature cycling chamber: must achieve ramp rates of at least 5°C/min, and ideally 10–20°C/min for efficient ESS. Look for chambers with fast pull-down and pull-up rates.
• Combined temperature/vibration (AGREE) chamber: combines a thermal chamber with an integrated vibration table. Used for simultaneous temperature and vibration ESS.
• Vibration table: standalone electrodynamic or pneumatic vibration systems used for vibration-only screens.

Indeecon's temperature cycling chambers are well-suited for ESS programmes, with fast ramp rates and precise temperature control.

ESS Test Standards

• MIL-HDBK-2164A — Environmental Stress Screening Process for Electronic Equipment
• IEST-STD-ESSEH — ESS Handbook (Institute of Environmental Sciences and Technology)
• MIL-STD-810 — Various environmental methods used as ESS inputs
• IEC 60068 — Environmental testing parts (basis for many ESS temperature/humidity profiles)

Who Uses ESS Testing?

• Defence & aerospace: ESS is often contractually required for military electronics under US DoD acquisition regulations.
• Industrial electronics: PLCs, motor drives, and process control equipment manufacturers use ESS to improve product reliability.
• Telecommunications: Base station equipment and infrastructure electronics are commonly ESS screened.
• Medical devices: ESS is used to improve quality confidence for life-critical electronics.
• Automotive electronics: Increasingly used for ADAS, powertrain, and safety-critical modules.

How to Design an Effective ESS Profile

An effective ESS profile must be tailored to the specific product. Key steps include:

• Define the thermal extremes: based on the product's design margins (from HALT data or specification), set the high and low temperatures for cycling.
• Set the ramp rate: faster ramp rates (10–20°C/min) are more effective at precipitating solder joint failures. Ramp rate is limited by the product's thermal time constant.
• Determine the number of cycles: typically 10–20 temperature cycles are sufficient for an initial ESS profile. This should be validated by monitoring the defect precipitation rate.
• Define the vibration profile: random vibration from 20–2,000 Hz at a defined overall Grms level (typically 6–10 Grms for production ESS).
• Monitor and optimise: track failure rates and types. If no defects are being found, the screen may be over-designed. If field failures continue, the screen needs strengthening.

Summary

Environmental Stress Screening is one of the most effective reliability tools available to electronics manufacturers. By shifting latent defect failures from the field to the factory, ESS reduces warranty costs, improves customer satisfaction, and protects brand reputation.

Indeecon's temperature and humidity test chambers are well-suited for ESS programmes, with fast ramp rates and precise temperature control. Contact our team to discuss your ESS chamber requirements.

Frequently Asked Questions

What is the difference between ESS and burn-in?

Burn-in typically involves operating products at elevated temperature (static, no cycling) for an extended period. ESS uses thermal cycling and/or vibration, which are significantly more effective at precipitating latent defects — especially solder joint failures — in fewer hours.

How many temperature cycles does ESS require?

Typically 10–20 cycles for initial ESS programmes. The exact number should be determined by defect precipitation analysis and validated against field return data.

Can ESS damage good products?

A well-designed ESS profile uses stresses within the product's operating margins and consumes a small fraction of its useful life. Overly aggressive profiles (excessive temperature range or vibration) can introduce new damage. HALT testing establishes the operating and destruct limits to prevent this.