When we manufacture any object, it must operate in a given environment. This means it must be able to withstand the effect of solar radiation, temperature, humidity, dust, high and low pressure, electromagnetic interference and so on. Usually we build a structure keeping this in mind. We pick objects that we know will be unaffected by the environmental conditions. Nevertheless, we have to carry out various environmental testing to ensure that the final structure will behave in the desired manner in its normal working conditions.
One of the environmental tests revolves around the temperature and humidity. The preferred instrument to carry out this test is the temperature and humidity test chamber. The chamber is used for testing the prolonged effect of humidity and a given temperature on a given object. It has wide usability across a range of industries that include pharmaceuticals, rubber and plastic. The benefits of such a test are many including:
- Improvement of industry standards
- Ensuring safety of the overall structure, especially where components parts are exposed to high temperature and humidity.
- Comparative analysis on different objects, materials, structures and products
- Development of more resistant material
- Ensuring the longevity of products
- Developing special materials and alloys that can be used in extreme conditions
Co-relation between temperature and humidity
Humidity testing is often accompanied with temperature testing. The two may seem completely unrelated. But they are quite inter-related. The relative humidity is, after all, the amount of moisture present in the air as a percentage of the maximum amount that it can hold at a given temperature. We find that we cannot control the humidity in an environment without manipulating the temperature. The air is capable of holding more moisture at a higher temperature. Hence, we have to change the temperature in order to test an object under varying humidity conditions.
Such testing equipment becomes vital in products where normal operation can raise the component temperature or where the product is used in extreme conditions like on the sea. But the question is, how does such a chamber work?
The Working of a Temperature and Humidity Test Chamber
The purpose of a temperature and humidity test chamber is to test the working of a given object under different environments, specifically under fluctuating humidity and temperature. The test can be performed in a static test where the given temperature and humidity remains constant. It can also be performed to check the level at which an object will start to disintegrate. All temperature and humidity test chamber are hence, not the same. We use different methods to manipulate the temperature and humidity in a chamber. Moisture is controlled by manipulating the temperature of the water. Cooling and heating devices are common for this manipulation.
There are different methods employed in such tests. Few of them are:
Steam generator: This chamber resembles a tank. It is fitted with immersion heaters. The function of the heaters is to raise the temperature of the water in the tank, generating steam. The steam then rises to the top. This is where we have heaters and cooling coils. The simplicity of the method makes it possible for us to use this method in big chambers. The water vapour presence is quite consistent, giving this test its reliability.
Atomiser: Here we use a spray nozzle to atomise the water. The water when passing through the heater, is heated instantly. This method is again very simple and extremely effective in creating conditions of high humidity. It is also considered efficient because the stress on heaters is quite low. This ensures that there are fewer chances of heaters burning out and the electricity consumption is kept low.
Water bath: Some chamber also use the water bath. The water bath is fixed with heating and cooling coils. The water vapour is created by this heating of the water bath. The difference from steam generator here is in the quantity of water which is very little. It also does not depend on the boiling of the water, which means that there is less mineral deposit. This makes the chamber easy to maintain as it can cleaned quickly.
These are the most common methods of manipulating the two important factors in a temperature and humidity test chamber. These are easy, simple, efficient and effective. This also makes them quite popular.