2010 (11) May (1) April (2) March (7) the use of a computer and its accessories in the prep

Hygrometers preparation: a Yasser Alwan, Chief, Division bain marie food warmer of Geography bain marie food warmer secondary Salahuddin - Aden Introduction: water vapor is one of the components of the atmosphere for Erd.hnak are several ways to set the amount of water vapor in the air. A mixing bain marie food warmer ratio: the ratio between the mass of water vapor to the mass of dry air, which is associated with water vapor. (B) Vapor Pressure: is the partial pressure of water vapor as a vehicle gaseous atmosphere and measured Balhectopascal. (C) moisture content: (humidity quality): is the ratio of the mass of water vapor to the mass of moist air, which is associated with him. D Relative humidity: bain marie food warmer is the ratio of the vapor pressure bain marie food warmer to the real pressure saturated steam at a temperature of the air. Methods of measuring air humidity: classified methods of measuring air humidity used for the purposes of research and application to: 1 thermodynamic bain marie food warmer method: bain marie food warmer (Almusrd-scale atmospheric humidity) 2 ways to change based on the dimensions of the material bain marie food warmer such as hair Almstrtabh 3 Ways electrical resistance bain marie food warmer method 4 Capacity 5-way electric absorption (absorption of calcium chloride moisture) 6 condensation method (hygroscopic dew point and freezing point) will explain the common methods used in our measurement as follows: 1. way thermodynamic (Psychrometer) bain marie food warmer consists Alsakromitr (Almusrd- scale atmospheric moisture ) of the budget be similar heat along one called Libra dry and the other wet and be covered with a thin cotton fabric or synthetic silk and keep hydrated with pure water. - Whenever the air was drier whenever evaporation from the wet cover more speed and the difference in temperature between the wet and dry Mezzanine more. - There are two ways Alloys Used to measure and calculate the moisture from Alsakromitr, namely: - (a) Using natural ventilation bain marie food warmer or free (Dabbling Permanent): hanging priming balance moistened in water and keep the onion moist due to capillary along Wick then measured the temperature of the mezzanine and the calculation of humidity using the equation of a private or using Table humidity. . (B) method of ventilation commodes or compulsory: is the use of a fan at a constant speed of between 2.5-10m / s is follow the steps below to read account balances and humidity: - 1 wetting balance wet. 2-run fan. 3 wait for two or three minutes or until the temperature reading balance wet fixed. 4 Balance dry reading. 5. read Libra wet. 6 calculate the relative humidity of the ruler of moisture or humidity table. - Prefer to use this method in the main stations so as to accuracy more than one way free ventilation. - The following table shows the calculation of the difference between the moisture balance bain marie food warmer of dry and wet. The difference between wet and dry relative humidity makes no difference 100% 0.5 96% 1 93% 1.5 89% 9 44% 15 17% 18 5% sources of error in the way thermodynamic (Alsakromitr) 1 error Almusenai thermometers (accuracy scales). 2 errors resulting from ventilation. 3 errors resulting from lack of clean water and seersucker. 2-way based on the dimensions of change Almstrtabh material (such as hair) - changing bain marie food warmer the number of organic material dimensions change depending on the moisture content. bain marie food warmer - Use human hair after degreasing is a perfect for measuring relative humidity since the seventeenth century. Increasing the length of hair between 2-2.5% on average for the change zero - 100% relative humidity and the length of the hair is usually between 15-20 cm. - Hair is very sensitive to pollution and the accumulation of grease result tactile therefore hair should be cleaned with materials such as alcohol, especially on a regular basis. devices used to have to measure relative humidity: Registered humidity ((Hygrograph. Device is being whereby registration humidity and consists bain marie food warmer of: a sensor: Here he hair and be in the form of a package to give strength to move the mechanical device. B group winches: is Total responsible for the transfer of the change in the length of the hair to the map. (c) The time: either be daily any spin cycle full within 24 hours or weekly spin cycle within 72 hours and put the map on the time to be recorded readings by which compares the day with readings Alsakromitr where you can good hardware measurement of relative humidity at temperatures cationic accurately 5%. sources of error: 1 change zero: This is caused by pulling the hair more than they should because of dealing coarse and be sensitive and accurate device may have been affected as well. 2 deposits grease, dirt and dust: Makes Hair Alostrtabah properties (moisture absorption) bain marie food warmer worse because of pollution or the wrong deal, which is due to damage or gradual deterioration in sensitivity bain marie food warmer and accuracy. bain marie food warmer 3 Effect of temperature on the coefficient of the slowdown, the negative thermal bain marie food warmer coefficient of slowdown, and Azdeadeh with low temperature.
2010 (11) May (1) April (2) March (7) the use of a computer and its accessories in the preparation of educational means ... wind solar radiation humidity atmospheric pressure Atmospheric Pressure arises pressure ... Pictures erosion factors, the problem bain marie food warmer of the earth's surface February (1) 2009 (5) September (3) August (2)