Climate Test Chamber Product

Overview

A climate test chamber subjects products to controlled temperature and humidity so engineers can verify how they behave across the conditions they will meet in service. Electronics, automotive parts, pharmaceuticals, packaging, and materials are placed inside and run through profiles — soaks at temperature extremes, humidity exposure, and repeated cycling — to expose weaknesses such as condensation faults, thermal expansion failures, or accelerated aging. Standards like IEC 60068 and various automotive and pharmaceutical stability protocols define the conditions these chambers reproduce.

Holding a stable point anywhere in a range from well below freezing to nearly 200 °C, at a chosen humidity, means continuously balancing opposing processes. The chamber always cools and always can heat; the controller trims the two against each other to settle precisely, and it adds or removes water vapor to hold humidity. This balancing approach gives fast, stable control but means the refrigeration and heating systems run together rather than one at a time.

Construction

Cooling comes from the Refrigeration System system, a vapor-compression circuit. For setpoints down to −40 °C and below, two stages are cascaded: the Compressor units feed a Condenser that rejects heat to room air through the Condenser Fan, an Expansion Valve meters refrigerant into the Evaporator inside the air path, and a Hot-Gas Bypass Valve modulates capacity so the system can hold steady near setpoint rather than cycling. Against this constant cooling, the Heating System system applies finned Heating Element heaters switched by a fast Solid-State Relay, guarded by a Thermal Fuse against runaway.

Humidity is managed by the Humidity System system. To raise humidity, the Steam Generator flashes purified water to steam, fed on demand through the Humidity Feed Valve; to lower it, the cold Dehumidification Coil surface condenses moisture out of the air. The Air Circulation system ties everything together: a Blower Motor drives air past the heaters, evaporator, and humidifier, and the Air Baffle distributes it evenly so the test space stays uniform.

The Cabinet & Door isolates the conditioned volume. A welded stainless Inner Liner resists corrosion from condensation and steam, thick Wall Insulation limits heat leak across the wide range, and a gasketed Door with a heated Door Gasket seals the opening without frosting. A sealable Cable Port passes instrumentation cables to a powered device under test.

How it works

The Programmable Controller runs the chamber as a programmed sequence of segments, each specifying a target temperature, humidity, and ramp rate. A PID loop reads the Control RTD in the air stream and continuously sets the heater duty against the running refrigeration to hold temperature within tenths of a degree. Humidity is derived from a Wet-Bulb Sensor sensor: the depression of the wetted-wick temperature below the dry-bulb reading gives relative humidity, and the controller calls for steam or dehumidification accordingly. The IO Board and its relays switch the compressors, heaters, valves, and fans.

Because a control fault could destroy the load or the chamber, an independent Temperature Limiter watches temperature on its own sensor and cuts all power if a limit is crossed, while a Pressure Sensor protects the refrigerant circuit and a Water Level Sensor sensor keeps the humidifier from boiling dry. Humidity testing consumes water steadily, so the Water System supplies it: a Water Reservoir feeds the humidifier through a Coolant Pump and a Water Filter that removes minerals which would otherwise scale the steam generator, and a Condensate Drain carries condensate away. Profiles can run for days, cycling between extremes thousands of times to compress years of field exposure into a controlled, repeatable test.