In industrial processes, the presence of hot or cold spots and surfaces is relatively frequent, generating significant increases or decreases in the temperature and humidity conditions of the environment. These variations, in some cases, can be very significant, and can have a negative impact on the operator. The latter, in turn, can make physical efforts that cause an increase in body heat, which together with the heat coming from his environment, can cause the destabilization of his body thermal balance. To compensate this thermal imbalance, the human being has a thermoregulation system (basically constituted by the superficial blood flow and the production of sweat), which avoids situations of decompensation in the thermal balance of his body.
Dry Air Temperature
It is commonly known as air temperature. It can be measured with a simple mercury thermometer whose scale reaches up to 50º C. The only precaution to be taken is to shield the thermometer bulb so that it is not directly exposed to the influence of radiant energy sources. There are other types of measuring instruments such as: thermocouples, thermoresistances and thermistors.
Wet air temperature
This temperature, together with the dry temperature, gives a measure of the degree of humidity of the air in the environment surrounding the worker. Normally, the wet temperature will be lower than the dry temperature. The greater the difference, the lower the ambient humidity. When both temperatures coincide, the air is said to be saturated with moisture. To measure the wet temperature you can use a simple mercury thermometer whose bulb is covered with a cotton wick moistened and placed in a container with water.
This temperature gives an indication of the amount of heat the worker receives as a result of proximity to hot spots or surfaces. To measure this temperature, the bulb of a mercury thermometer is placed inside a 15 cm copper sphere. The diameter of the sphere is painted black on the outside.