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Gauge (bore diameter)

The gauge of a firearm is a unit of measurement used to express the diameter of the barrel. Gauge is determined from the weight of a solid sphere of lead that will fit the bore of the firearm, and is expressed as the multiplicative inverse of the sphere's weight as a fraction of a

Rain gauge

A rain gauge (also known as a udometer or a pluviometer [Pluviograph ] or an ombrometer or a cup) is a type of instrument used by meteorologists and hydrologists to gather and measure the amount of liquid precipitation (solid precipitation is measured by a snow gauge) over a set period of time.


The first known records of rainfalls were kept by the Ancient Greeks about 500 B.C. This was followed 100 years later by people in India using bowls to record the rainfall. The readings from these were correlated against expected growth, and used as a basis for land taxes. In the Arthashastra, used for example in Magadha, precise standards were set as to grain production. Each of the state storehouses were equipped with a standardised rain gauge to classify land for taxation purposes.

While some sources state that the much later cheugugi of Korea was the world's first gauge, other sources say that Jang Yeong-sil developed or refined an existing gauge. In 1662, Christopher Wren created the first tipping-bucket rain gauge in Britain.


Most rain gauges generally measure the precipitation in millimeters. The level of rainfall is sometimes reported as inches or centimeters.

Rain gauge amounts are read either manually or by AWS (Automatic Weather Station). The frequency of readings will depend on the requirements of the collection agency. Some countries will supplement the paid weather observer with a network of volunteers to obtain precipitation data (and other types of weather) for sparsely populated areas.

In most cases the precipitation is not retained, however some stations do submit rainfall (and snowfall) for testing, which is done to obtain levels of pollutants.

Rain gauges have their limitations. Attempting to collect rain data in a hurricane can be nearly impossible and unreliable (even if the equipment survives) due to wind extremes. Also, rain gauges only indicate rainfall in a localized area. For virtually any gauge, drops will stick to the sides or funnel of the collecting device, such that amounts are very slightly underestimated, and those of .01 inches or .25 mm may be recorded as a trace.

Another problem encountered is when the temperature is close to or below freezing. Rain may fall on the funnel and freeze or snow may collect in the gauge and not permit any subsequent rain to pass through.

Rain gauges should be placed in an open area where there are no obstructions, such as building or trees, to block the rain. This is also to prevent the water collected on the roofs of buildings or the leaves of trees from dripping into the rain gauge after a rain, resulting in inaccurate readings.


Types of rain gauges include graduated cylinders, weighing gauges, tipping bucket gauges, and simple buried pit collectors. Each type has its advantages and disadvantages for collecting rain data.

Standard rain gauge

The standard rain gauge, developed around the start of the 20th century, consists of a funnel attached to a graduated cylinder that fits into a larger container. If the water overflows from the graduated cylinder the outside container will catch it. When measurements are taken, the cylinder will be measured and then the excess will be put in another cylinder and measured. In most cases the cylinder is marked in mm and in the picture above will measure up to 25 mm (0.98 in) of rainfall. Each horizontal line on the cylinder is 0.2 mm (0.007 in). The larger container collects any rainfall amounts over 25 mm that flows from a small hole near the top of the cylinder. A metal pipe is attached to the container and can be adjusted to ensure the rain gauge is level. This pipe then fits over a metal rod that has been placed in the ground.

Weighing precipitation gauge

A weighing-type precipitation gauge consists of a storage bin, which is weighed to record the mass. Certain models measure the mass using a pen on a rotating drum, or by using a vibrating wire attached to a data logger. The advantages of this type of gauge over tipping buckets are that it does not underestimate intense rain, and it can measure other forms of precipitation, including rain, hail and snow. These gauges are, however, more expensive and require more maintenance than tipping bucket gauges.

The weighing-type recording gauge may also contain a device to measure the quantity of chemicals contained in the location's atmosphere. This is extremely helpful for scientists studying the effects of greenhouse gases released into the atmosphere and their effects on the levels of the acid rain.

Tipping bucket rain gauge

The tipping bucket rain gauge consists of a funnel that collects and channels the precipitation into a small seesaw-like container. After an amount of precipitation equal to 0.2 mm (0.007 in) falls, the lever tips, dumping the collected water and sending an electrical signal. The recorder consists of a pen mounted on an arm attached to a geared wheel that moves once with each signal sent from the collector. When the wheel turns the pen arm moves either up or down leaving a trace on the graph and at the same time making a loud click. Each jump of the arm is sometimes referred to as a 'click' in reference to the noise. The chart is measured in 10 minute periods (vertical lines) and 0.4 mm (0.015 in) (horizontal lines) and rotates once every 24 hours and is powered by a clockwork motor that must be manually wound.

The tipping bucket rain gauge is not as accurate as the standard rain gauge because the rainfall may stop before the lever has tipped. When the next period of rain begins it may take no more than one or two drops to tip the lever. This would then indicate that 0.2 mm (0.007 in) has fallen when in fact only a minute amount has. Tipping buckets also tend to underestimate the amount of rainfall, particularly in snowfall and heavy rainfall events.. The advantage of the tipping bucket rain gauge is that the character of the rain (light, medium or heavy) may be easily obtained. Rainfall character is decided by the total amount of rain that has fallen in a set period (usually 1 hour) and by counting the number of 'clicks' in a 10 minute period the observer can decide the character of the rain. Correction algorithms can be applied to the data as an accepted method of cor

Jewelry wire gauge - Wikipedia, the free encyclopedia

Jewelry wire gauge is a measure of the diameter or gauge of wire used in ...

From Yahoo Answers

Question:A coil is formed by winding 280 turns of insulated 20 gauge copper wire (diameter = 0.8 mm) in a single layer on a cylindrical form of radius 11 cm. What is the resistance of the coil? The resistivity of copper is 1.69 10-8 m. Neglect the thickness of the insulation.

Answers:Each turn has a radius of 11 cm + 0.4 mm = 11.04 cm circumference = 69.4 cm 280 turns are 19422 cm or 19.4 m Resistance of a wire in R = L/A is resistivity of the material in -m L is length in meters A is cross-sectional area in m A = r , r is radius of wire in m R = (1.69e-8)(19.4)/ (.0004) = 0.652 ohms .

Question:How many atoms are present in a 1.09-m length of 20-gauge copper wire? A 20-gauge copper wire has a diameter of 0.03196 in., and the density of copper is 8.92 g/cm3.

Answers:Updated: I originally used the diameter in the pi*r^2 formula instead of the radius (r = d/2). That has been corrected. Consider the length of copper wire as a cylinder: The volume of a cylinder is given by the area of the base * length. Given that the wire has a diameter, the base is basically a circle. the area of a circle with diameter "d" is pi * (d/2)^2 ( http://en.wikipedia.org/wiki/Volume ) and remember that d = 2*r. Since most of the units in this question are metric, lets start by converting the inches to centimeters. d = 0.03196 Inches * 2.54 cm/in = 0.08118 Centimeters r = d / 2 = 0.04059 cm The volume of the wire is given by V = pi * r^2 * length = pi * (0.04059 cm)^2 * 1.09 m = pi *(0.04059 cm)^2 * 109 cm = 0.56418 cm3 (approx) Given that the density of the copper is 8.92 g/cm3, the total weight of copper is the volume * the density wt = 0.56418 cm3 * 8.92 g/cm3 = 5.0325 grams (approx) To find out how many atoms, we need a reference weight. http://wiki.answers.com/Q/What_is_the_atomic_number_of_copper says that copper weighs 63.546 grams per mole. The number of moles in the length of wire is given by: wt of wire / wt of one mole, so 5.0325 grams in wire / 63.546 grams per mole = 0.0792 moles. Now, since 1 mole is 6.02 * 10^23 atoms, the number of atoms in the given wire is ... (0.0792 moles) * (6.02 * 10^23 atoms / mole) = 4.76784 * 10^22 atoms.

Question:How many atoms present in a 1.00m length of 20 gauge copper wire? A 20 gauge wire has a diameter of 0.03196 in. and the density of copper is 8.92 g/cm^3. So far I've gotten this: volume density mass atoms volume = [ (0.03196in / 2) (2.54cm / 1in) ] (pi) [ 1.00m(100cm / 1m) ]= 0.05175:721 cm (using density to convert to mass) 0.05175:721 cm (8.92 g Cu / 1 cm ) = 0.0461:674312 g Cu (using mass to atoms conversion) 0.0461:674312 g Cu (1mol Cu / 63.546g Cu) (6.022 * 10 atoms Cu / 1mol Cu) = 4.37:51026 * 10 atoms 4.38 * 10 atoms Cu Can someone check if this is right? Thanks for any help. The colons represent sigfigs.

Answers:Hi Emma I think you have made only one mistake. This is what I get: - diam of wire = 0,03196 in = 0,03196 X 2,54 cm = 0,0811784 cm Cross sectional area = (piD^2) / 4 ( This ie really the same as piR^2 ) Area = (0,0811784^2 X pi) / 4 = 5,17572 X 10^ -3 cm^2 Volume =100 X 5,17572 X 10^ -3 cm^3 = 0.51752 cm^3 ( You got 0,051757, thats 10 times less ) Mass of Cu = 0,5175 X 8,92 grams = 4,6167 g ( You found 0,04616 g ) So number of atoms = (4,6187/ 63,546) X 6,022 X 10^23 atoms = 4,375 X 10^22 atoms of Cu Now the density of copper is known to only two decimal places therefore round the answer off to rwo places Number of copper atoms = 4,38 X 10^22 I agree with your answer but not your calculations - if you know what I mean,


Answers:man dont listen to those guys. It is just fine to do that.