Per mil
The term parts per thousand (from Latin per, " of", " in relation to "; mille " thousand ") is used in amounts expressed in thousands of fractions. This corresponds to one thousandth of the number 0,001. Per mille information is usually indicated by the degree sign ‰.
Definition
The blood alcohol is an auxiliary unit of ratio sizes with the meaning " one thousandth ". Through the trailing degree sign the front of it permillage is therefore divided by a thousand:
Examples
Calculation
It is the basic equation:
This results in:
And can be used as computational control formula:
Applications
Banking and Insurance
In thousandth specified parameters are, inter alia, to take in the insurance and banking. An example from the insurance industry is the indication of a loss frequency per 1000 risk.
Drinking and driving
The term per thousand referring colloquially to the alcohol content in the blood of the person. The blood alcohol content is usually expressed in parts per thousand, and can be calculated using the Widmarkformel and measured in the breath or blood. As a unit, the mass ratio is milligrams of alcohol per gram of blood (mg / g ): see Article blood alcohol concentration. With a handy Alcotest device, which is used for police checks or accident recordings usually on the road, and into which you put into blows, it can be determined that the person has alcohol concentration in the breath. The unit of measurement is the amount of alcohol in milligrams per liter of breath (mg / l). In this example, correspond to 1.0 mg / l breath alcohol concentration of 2.1 mg / g of blood alcohol concentration ( = 2.1 per thousand ). The exact alcohol content - it should be too high - is then determined at the police station with either a far more sophisticated breathalyzer or by a doctor through a blood alcohol measurement ( with a small withdrawal of blood from the person concerned ).
Incline / decline of railways
While roads the tendency indication usually is in percent, the horizontal tilt of lines of railways ( gradient ) is given in parts per thousand. The value corresponds to the height difference in millimeters per meter of horizontal distance ( or the height difference in meters per kilometer), so the tangent of the slope angle. The value is used to calculate the maximum crossbow draw or trailer on inclines, may contribute to determining the speed limit in the gradient (depending on the braking force and draw weight ).
In Switzerland, the line is considered with inclinations up to 10 ‰ as flat sheets. In Germany, according to the Railway Construction and Operating Rules 12.5 ‰, the maximum tilt control for main lines.
Routes with an incline over 50 ‰ can be driven normally only with the help of gear drive. Exceptions are, for example, the tram of Lisbon, whose maximum slope is 13.5 %, that is 135 ‰, the Uetlibergbahn with 79 ‰, the Bernina Railway with 72 ‰ or Erzbergbahn with 71 ‰.
The degree sign ‰ (Unicode U 2030 ) is the result of a% character, which in turn was created by shortening from the Italian per cento. Typographically is always a space between the number and the degree sign set.
In the German standard DIN 5477 from February 1983 details on the correct application of parts per thousand are fixed. Thus, its use is limited to use in " the indication of quotients of numbers or quantities of the same dimension, including the money ". The international standard ISO 31-0 Quantities and units - Part 0: General principles of 1992 recommends avoiding the sign ‰. According to DIN 5008, the use of word processing by the sequence o / oo is possible.