Knowing the value of the cooling ability of the catheter and the ambient temperature, it is possible empirically
Arrow indications
The difference in readings is 5680 m – 4200 m = 1480 m The desired air velocity is 1480: 600 = 2.46 m / s.
Example:
The manual vane anemometer is more sensitive and suitable for determining the air velocity in the range from 0.5 to 15 m / s. In this device, the receiving part is a wheel with light aluminum wings fenced by a wide metal ring. This device is designed to test the efficiency of ventilation units and measure the speed of air movement in a production environment. The transmission of the rotation of the wheel to the dial hands is similar to the system of the previous device. In observations, the direction of air currents should be perpendicular to the plane of rotation of the wheel. The duration of observation is 3-4 minutes.
To determine low air velocities, an indirect method is used, based on taking into account the cooling intensity of the heated device. The cooling ability of air in millikaloria of heat lost from 1 cm 2 of the surface in 1 second is determined using a katermometer (from Greek kata – movement from top to bottom) – a special alcohol thermo formula to calculate its speed. To calculate air velocities of less than 1 m / s, use the formula:
V = (H / Q – 0.20) 2 : 0.40 2
To calculate air velocities greater than 1 m / s
Touch with skin, increase heat transfer. Moreover, if the air temperature is lower than the skin temperature, then the heat transfer occurs mainly by convection, and if higher, then by evaporation. It has been established that a violation of thermoregulation may not occur if the air temperature is 30 ° C at a relative humidity of 80–90% or 40 ° C at a relative humidity of 40–50%, but this upper limit of the permissible combination of meteorological conditions has been established for humans. being at rest, and significantly reduced when he performs physical work.
Prevention of violations associated with the overvoltage of the thermoregulation system consists mainly in the implementation of measures that ensure the creation of comfortable thermal conditions through the use of rational clothing, nutrition, and the provision of a normal microclimate in homes, workrooms, and others. Nie has hardening of the body.