1what is the temperature

The temperature is hot and cold degree of the denoted objects. When a pot of water boiling time, another pot of water may be slightly hot. At this time, as long as the hand slightly close to some, can feel which has fast pot of water boiling, that is the temperature sensation. In other words, when A, B two object contact, such as the heat from the A object to the B object, then the A temperature is higher than that of B; otherwise, B temperature higher than A. If A, B two objects without intermediate heat exchange, then the object temperature equal. Through long term experiments and theoretical studies show that, regardless of whether the two objects contain the quantity of heat is a number respectively, heat always from high temperature object to a cold object, namely temperature determines the heat. According to molecular motion, temperature is large moving average molecular kinetic energy logo, temperature, molecular motor speed; conversely, when the temperature is lowered, molecular motion speed. If the temperature is reduced to molecular motion completely stopped, the temperature is known as the" absolute zero", but could not reach the absolute zero.

2 what is the humidity?

Humidity is used to indicate the moisture in the air or air moisture content degree of physical quantity. Humidity size used water vapor pressure, absolute humidity, relative humidity and the dew point temperature to said. Air around us, always mixed with water vapor, water vapor accounts for the proportion of air as the temperature varies, the higher the temperature of air absorbing moisture more. Under certain temperature conditions, a volume of air can only hold a certain amount of water, if water vapor to air can hold water limit, when the air is saturated, the relative humidity is100, under the condition of saturation moisture evaporation, no longer.

3 what is the scale?

Need to measure temperature in refrigeration technology in many situations, such as refrigeration compressor suction temperature, exhaust gas temperature, cooling water temperature, oil temperature, etc.. Measurement of the temperature scale is referred to as scale, any scale to define basic point and each of the degree of numerical. The international system of units ( SI ) basic scale is the thermodynamic temperature scale, also known as the absolute scale of temperature. Using the thermodynamic temperature scale indicates the temperature, called the thermodynamic temperature or absolute temperature. Thermodynamic temperature is denoted by T. Thermodynamic temperature is the unit of Kelvin, referred to as open, international symbol is K, it is the international system of units in one of the seven basic units. It is internationally recognized as the thermodynamic temperature of zero - 273.15DEG C, absolute zero. On each of the degree of size, thermodynamic temperature and temperature are the same, so the thermodynamic temperature to Celsius temperature relationship is: T = t+273.15. In engineering calculations generally take 273degrees of absolute zero, then T = t+273.

4what is the pressure and pressure?

Objects on the unit area of a force called the pressure, in engineering technology conventionally called the" pressure", in P, Pa as unit (PA), in which absolute vacuum ( zero ) as a reference to said pressure ( PA ), called the absolute pressure; barometric pressure as a reference to the actual to indicate the pressure ( PG ) called the gauge pressure standard atmospheric pressure; with reference to said pressure ( PS ) called the sealing pressure; to less than the actual atmospheric pressure gauge pressure ( also called vacuum) known as negative pressure. The international system of units ( SI ) with Pascal as the general unit of pressure, to Pa or Palmer said. As for the 1square meters ( square meters ) area of the force1N ( Newtonian ) is1Pa ( Pascal ), with the formula expression is as follows:

Pa = N / square meters tips: pressure, pressure unit conversion:1bar ( BA ) = 10* Pa =1N / s * ( Newtons per square meter ),1 standard atmospheric pressure = 1.013* 10* Pa;1mmHg ( millimeter of mercury column ) = 133.322Pa. 5what pressure?

The weight of the air pressure generated on the object is called the atmospheric pressure, referred to as the pressure. The unit of pressure is two millimeter of mercury column and mb. Among them, in the mercury column height to said pressure level unit mm ( mm ). For example, air pressure is 760mm, is expressed at atmospheric pressure and the height of the mercury column760mm generated by the pressure.

Absolute pressure gauge pressure6and what is the difference?

General pressure gauge indicated by the gas pressure, and not representative of the real gas pressure, and beyond the atmospheric pressure value, that is to say no to atmospheric pressure are included, gauge pressure is atmospheric pressure zero count, also known as indicative of stress or pressure. Gauge pressure and atmospheric pressure is an absolute pressure, it has absolute vacuum zero calculation. When the seal gas pressure within the container below atmospheric pressure, whereby the vacuum negative pressure, also known as. Usually760 mm mercury ( at 0 degrees ) for the standard scale. If the directed out of the container below atmospheric pressure readings, called vacuum degree. According to the above results, can use a mathematical formula to express the absolute pressure and the pressure gauge, vacuum degree of the relationship between. When A > B, A = B+C when A < B, A = B-C, B, C, A in D were expressed in absolute pressure, the local atmospheric pressure, pressure gauge and vacuum.

7 what heat?

The only heat transfer process, the high temperature object to energy (internal energy ) delivered to the low temperature object, the energy that heat. The commonly used Q said, it is the object in the state change occurs during the process of energy conversion box changes in a measure. In the international system of units ( SI ), the heat units with Joule ( J ) or kilojoules ( KJ ) said ( engineering according to the traditional custom card ( CAL ) or kilocalorie ( deduct kcal ),1cal =4.1868J )

8what is the specific heat?

Unit mass objects each increase or decrease once the heat absorbed and released, known as the object of the specific heat, commonly used C. With the formula expression is as follows: C = Dq / dt : dQ is an infinitesimal thermodynamic process in heat absorbed by the system, dt as the temperature changes. Specific heat of unit depends on the heat unit and the unit quantity. The solid, liquid, no unit usually use the unit of mass ( kg ), the specific heat of C unit kJ / ( kg K ), called the mass specific heat. On the gas in addition to the use of units of mass, are also commonly used standard volume ( square meters . K) and J / ( mol K ), corresponding to the known volume specific heat and the molar specific heat.

9what is the specific heat at constant pressure and constant volume specific heat?

Gas in the constant pressure and volume under the condition of constant heat when being heated, called respectively" the specific heat at constant pressure" and" constant volume specific heat". Constant pressure heating, the heat absorbed by gas so that gas humidity rising, but also overcome the force and expansion work. Therefore the unit mass of gas temperature of1 DEG C than the constant volume heating absorbs more heat, that set pressure specific heat ratio to the heat capacity.

10what is the specific heat ratio?

Gas specific heat at constant pressure and constant volume specific heat ratio, known as the specific heat ratio ( or adiabatic index), often with the letter "K" said. Various gas specific heat ratio in compressor, gas temperature and compression ratio under the same circumstances, specific heat ratio is larger, the adiabatic compression the higher the temperature.