Instruments for measuring air temperature
The air temperature in the rooms is measured by thermometers, which are divided into measuring (alcohol, mercury, electric), designed to determine the temperature at the time of observation, and fixing (minimum and maximum), allowing to obtain the minimum or maximum temperature value for a certain period of time (day, non-lethal day).
The maximum (mercury) thermometer is used to record the highest temperature for a certain period of time. Mercury forming a convex meniscus, with
as the temperature rises, it rises along the capillary, and when it decreases, it shrinks and moves back. The temperature is determined by the upper convex part of the meniscus of mercury. The operating position of the thermometer is horizontal (Fig. 1a).
The minimum (alcohol) thermometer is used to determine the lowest air temperature in a given period of time. Inside his capillary tube, in alcohol, is a dark glass pointer needle with bulges at the ends in the form of pin heads. Before observation, the lower end of the thermometer is lifted, while the pointer needle under the action of its own gravity drops down to the meniscus of alcohol. Alcohol, forming a concave meniscus, with a decrease in air temperature carries the pointer towards the reservoir, and when it rises, the pointer streamlined with alcohol remains in place. The operating position of the thermometer is horizontal (Fig. 1b).
For observing the tamper air can Aturi uses vatsya dry bulb hygrometer Ass mana , appliance, prednaznachenno- th to measure the air humidity. Scale value of its scale 0,2 o C .
For continuous recording of air temperature fluctuations over a certain period of time (day, week), recording instruments are used — thermographs-recorders (from Greek thermo – heat and gr apho – I write) .
The thermograph consists of a temperature-sensing part of the device – a bimetallic plate, the change of curvature of which, in accordance with the change in air temperature, is transmitted to the arrow with a pen using a system of levers, which records the thermogram on a moving tape, grafted by days, hours and degrees of temperature . The tape is put on a cylinder that rotates with a clockwork at a speed of one revolution per day (or per week, if the thermograph is weekly).
Currently, there are modern automatic devices that can measure temperature, humidity and the level of illumination. For example , a TKA-PK-UV light meter .