Hygrometers and ThermohygrometersDepending on the temperature, ambient air is able to absorb a certain percentage of water and it can also release its humidity to the environment. In industrial processes, in warehouse storage, in museums, libraries and even in dwellings and at workplaces the effects of high or low air humidity can cause damages to products, objects and also to health.
For this reason, monitoring of the relative air humidity is necessary, and this can be done by means of hygrometers, which are often combined with thermometers (thermohygrometers) and which then can also indicate temperature and dew point.
A Hygrometer is an instrument used to measure the quantity of water vapour present in air. Hygrometers can measure relative humidity over the range of 0 to 100% RH, but in most instruments, this range may be more limited depending on the sensor type. Relative humidty is expressed as the ratio of the amount of water vapour present in the air or gas, to the quantity which would reach saturation, saturation being 100%.
Hygrometers for IndustryIn many manufacturing processes the measurement of relative humidity (%RH) is important, as many products are sensitive to variations in humidity. Therefore humidity needs to be measured and controlled for teh end products to be consistent in both quality and performance.
There are a wide range of applications for % RH measurement in the following industries:
The pharmaceutical industry is one of the largest users of humidity instrumentation as products can be sensitive to variations in humidity levels. Food manufacturing processes rely on humidity control, as food preservation techniques are often focused on limiting the activity of water.
Paper and paper based products are highly sensitive to humidity and moisture levels.
During production, storage and distribution, the monitoring of humidity can have significant benefits on quality.
Monitoring Humidity for Better Health
Humidity is an essential element of climate control in buildings for optimum comfort and energy conservation.
If a building is too damp and the humidity level ist too high (above 70%RH), not only does mould develop but it can encourage dust mites to breed in carpets and mattresses.
Conversely, if the humidity level is too low (below 25%RH) it can cause respiratory discomfort. Ther regular monitoring of humidity levels in building can improve health.
The dew point is defined as the lower temperature to which air must be cooled in order for condensation (saturation) to occur. The dew point is dependent on the concentration of water vapour (%RH) present.