Measurement of Length

An example of an electronic distance measuring Instrument used in surveying. 

---

The above rules can be similarly applied to the conversions of volume and length measurements. While the weight and volume measurements are the most commonly used, the measure of length is used in measurements such as the patient s height and body surface area. The liquid and length measures are provided in Tables 2.2 and 2.3. 

If we knew how a physical property changed as we altered we could deduce how this property depended upon b and N. several statistical measures of length of the chain, for example of gyration ... 

Angstrom. A measure of length used to denote distances between atoms and dimensions of molecules. Approximately 10" centimeter. The abbreviation is A. 

Meter a unit of measurement of length in the metric system. One meter equals approximately 39.37 inches in the English system. 

Most of the problems in this book use the English measures of length, volume, and weight. But metric measures are very important to know, because of the great incidence of foreign travel and trade with other countries that use metrics. 

The metric system, or Systeme International d Unites (SI system as it is commonly known), is the predominant system of measurement in the world. In fact, the United States is one of only about three countries that do not commonly use the metric system. The metric system attempts to eliminate odd and often difircult-to-remember conversions for measurements (5,280 feet in a mile, for example). It is a decimal-based system with standard terminology for measurements of length, volume, and mass (weight). It also uses standard prefixes to measure multiples of the standard units. 

Micrometer - An instrument by which highly accurate minute measurements of length, depth, or thickness may be made. 

The conventional representation of numbers using scientific notation is not always followed. For example, we might represent a bond length as 0.14x 10-9 m rather than 1.4 x 10-10 m if we were referencing it to another measurement of length given in integer unit multiples of 10 9 m. 

Basic Measurements Under this term are included the measurements of length, mass, surface, volume, time, etc... 

The measures of length, volume, mass, energy, and temperature are used to evaluate our physical and chemical environment. Table 2.2 compares the metric system with the more recently accepted SI system (International System of Units). The laboratory equipment associated with obtaining these measures is also listed. 

The dimensionless number H2 is, in fact, the well-known Reynolds number, Re, even though it appears in another form here. Now, we will explain the structure that a dimensionless number must have in order to be called a Reynolds number. (This example is equally valid for all other named dimensionless groups.) The Reynolds number is defined as being any dimensionless number combining a characteristic velocity, v, and a characteristic measurement of length, 1, with the kinematic viscosity of the fluid, v = p/p. The following dimensionless numbers are equally capable of meeting these requirements ... 

Now we will examine the flotation process taking place in the flotation cell (s. Fig. 3 a) of a given geometry (characteristic linear measurement of length being the cell diameter D). 

The present HVI system as developed in the United States has been used principally for marketing of the U.S. cotton to the U.S. textile industry. With the disappearance of the U.S. textile industry there has been an impetus toward the standardized testing of cotton on a global basis [604]. The concern is that HVI measurements of length, strength, fineness, color, and trash were probably sufficient for marketing Upland cotton to an industry concentrating... 

The target quantity of this stirring operation, the mixing time 6 or 0m - in the following for the sake of simplicity shortened to 0 - depends, for a material system without density and viscosity differences and for a particular stirrer type under given geometric conditions, only upon the characteristic measurement of length (stirrer diameter d), both material parameters (density p and kinematic viscosity v) and the stirrer speed n ... 

Another measure of length is the equivalent hydraulic radius, rh, determined inversely from saturated or unsaturated flow experiments. By comparing Darcy s equation with Poiseuille s law, and invoking a capillary bundle model, one obtains the following definition of rh (Kutflek Nielsen, 1994),... 

Frequency measurements, which are amongst the most accurate measurements made, form a basis of, on the one hand, practical measurements of length as defined in terms of the SI metre for example, and on the other, determination of universal physical constants such as the Rydberg constant. Atomic physics lies at the heart of these measurements, providing the tools and methods of laser spectroscopy as well as the theory of atomic structure and atom-light interaction with which to interpret the results of measurements and relate them to other fields of physics. 

As a rule, coefficients of linear expansion-contraction are calculated based on measurements of length of samples/ree/y placed, that is, in completely unrestrained conditions, under carefully controlled temperature. Freely placed here means that they are under unrestricted temperature-driven movement. For example, for GeoDeck boards the temperature coefficient is equal to 3.58X10 1/°F. This followed from an experimental fact that a 2-in. long GeoDeck sample initially placed at 30°F became 12.17 mil (0.01217 in.) longer at 140°F. 

Old French Linear Measure. The former measures of length in France were the... 

Roman Measures of LenglJi. Tho Roman measures of length or distance were feel, uubils, paces, stadia, and miles. 

Metriool Measure of Capaetkf-6000 Metrical Measure of Length, .6016 Metrioal Measure of Soriaoe.. 60BB... 

A new use for ammonia, NHS, has been foundf. The mean solar day is not absolutely constant. Owing to variations in the rate of rotation of the earth on its axis there is a fluctuation of 1 second in every 20 to 30 million seconds. In addition to this there is a slight lengthening of the solar day due to a slowing down of the earth s rotation, through tidal action mainly, which amounts to about 1 second per day every 120,000 years. This has raised the question as to whether or not it might be possible to check time intervals by some absolutely constant wave motion on the lines adopted for measurements of length (p. 308). This problem is in course of solution by the invention of the atomic clock , as it is... 

Measurements of Length, Volume, and Mass Uncertainty in Measurement Significant Figures Problem Solving and Dimensional Analysis Temperature Conversions ... 

---