The reliability of an engineering product is greatly influenced by its operating environment. During manufacture, transport, storage and service varying adverse
climatic conditions may be experienced affecting both performance and survival capability. Simulation of these conditions under controlled laboratory conditions
can both assist the design process and demonstrate that a product is fit-for-purpose.
This course provides an introduction to climatic testing with emphasis placed on the practical aspects of the subject. It includes the principles
of operation of climatic chambers, their construction, methods of heating, cooling and humidification. Instrumentation for measurement and recording of
conditions within the test chamber will be considered and the options available for temperature and humidity control will be discussed. Calibration procedures
will be covered, including the concept of measurement uncertainty. A comprehensive set of lecture notes is provided.
The course will cater for test engineers who have recently joined environmental test laboratories and those who are concerned with
product development, reliability and type approval testing as part of design assurance work. No prior knowledge of Climatic Testing is required
and mathematics will be kept to the minimum necessary for an understanding of the subject.
The syllabus includes:
temperature (steady state, diurnal cycling, rapid changes, thermal shock) effects, sensors, PRTs, colour codes, cold junction compensation,
extension wire, 2- 3- and 4-wire connections, measurement uncertainty, vapour sealing, chamber working space;
humidity (absolute, specific and relative), partial and saturated vapour pressure, humidity generation and removal,
dew point hygrometer, wet and dry psychrometer, psychrometric charts, sensor types;
chamber control (on/off, proportional, integral, and derivative), control strategies, loop tuning, alarms and trips;
heating and refrigeration plant, latent heat, evaporation and boiling, heaters, refrigerant gases, LN2 cooling, mechanical refrigeration, multi-stage systems;
vacuum generation and measurement, pump types, rapid and explosive decompression, altitude chambers, vacuum gauges;
solar radiation, irradiance, spectral characteristics, daily, seasonal and geographic variations, effects and simulation, lamp types;
pollution and contamination.