Today, on the ground outside our factory, six identical white cabinets were arranged in a row, the door locks were closed, the control panel was inspected for the last time, and waiting for packaging before loading onto the truck. They are six custom-built High & Low Temperature Chambers, and their destination is Thailand.
This order is a good example of what most of our export projects actually look like: not a standard machine pulled off the shelf, but a chamber sized and configured around one specific test profile.
Environental test chamber item:
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Item
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Specification
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Product
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High & Low Temperature Chamber (thermal cycling)
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Quantity
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6 units
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Destination
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Thailand
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Inner chamber size
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W 600 × H 500 × D 400 mm (≈ 120 L, customized)
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Test condition
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-40 °C → +75 °C, and +75 °C → -40 °C (bidirectional cycling)
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Platform temperature range
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-70 °C ~ +150 °C
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Heating element
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Spring-type (helical coil) heating wire
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Venting
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Top-mounted exhaust port
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Applicable standards
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IEC 60068-2-1, IEC 60068-2-2, IEC 60068-2-14
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The Test That Matters: -40 °C ↔ +75 °C
This customer is not running a simple "cold soak" or "hot soak". Their profile drives the chamber down to -40 °C, up to +75 °C, and back down again, repeatedly.
That up-and-down direction is where real product weaknesses show up. Every cycle makes materials expand and contract at different rates — solder joints fatigue, plastic housings crack at the ribs, adhesive layers delaminate, seals and gaskets lose elasticity, and conformal coating lifts off the PCB. A sample that happily survives 100 hours at a constant +75 °C can fail in ten cycles of -40 °C ↔ +75 °C.
Our job was to make sure the chamber can reproduce that window accurately and repeat it thousands of times, with the temperature uniform enough that every sample on the shelf sees the same stress.
Four Engineering Choices:
1. A chamber sized to the sample — W 600 × H 500 × D 400 mm
120 liters is a deliberately practical size. It is large enough for PCBAs in fixtures, small modules, sensors, connectors, battery packs, rubber and plastic parts, and packaged consumer goods — yet compact enough to sit in a normal laboratory or a production-side QC room without special foundation work.
Inside: a stainless steel (SUS 304) inner chamber with a removable shelf, a cable/lead port for powering or monitoring samples under test, and a large tempered-glass viewing window with internal lighting so operators can observe without opening the door and dumping the temperature.
2. Spring-type heating wire
For the heating side we use a spring-type (helical coil) heating wire rather than a straight element. Three practical reasons:
- Larger radiating surface — the coil geometry exposes far more wire area to the circulating air, so heat is released faster and more evenly instead of concentrating in one hot spot.
- Lower surface load, longer life — because the same power is spread over more wire, the element runs cooler for a given output. That means less oxidation, less embrittlement, and a much longer service life under repeated -40 °C → +75 °C cycling.
- Faster thermal response — low thermal inertia lets the controller track the ramp more tightly at the +75 °C plateau, which is exactly where temperature overshoot usually ruins a test.
3. Top-mounted exhaust port
The exhaust port on the top of the chamber is a small detail that solves several real problems:
- It relieves the pressure rise inside the working chamber as air expands on the way up to +75 °C, protecting the door seal and the window.
- It lets volatile substances released by the sample (plasticizers, solvents, adhesives, battery electrolyte vapour) escape instead of condensing on cold surfaces and on the viewing glass.
- It can be ducted straight to the outside of the building, which is what most Thai customers do when testing anything with an odour or an emission.
- For battery and capacitor testing, it can be specified as an enlarged pressure-relief / explosion-proof vent.
4. Headroom to -70 °C and +150 °C
Although this project is validated for -40 °C to +75 °C, the chamber is built on a platform engineered for -70 °C to +150 °C. In practice that gives the customer two things: the refrigeration and heating systems are never running at their absolute limit during routine tests (which is what keeps failure rates and drift low), and if a future product requires a deeper cold or a hotter soak, they can extend the specification on the same machine family instead of buying a new one.
Planning a Similar Chamber?
Tell us four things and we will come back with a drawing and a quotation within 24 hours:
Inner chamber size you need (or your sample dimensions)
Temperature range and whether you need cycling
Required ramp/hold profile and applicable standard
Sample type, weight and whether it generates heat or vapour during test
Por favor verifique seu email!
