Distance Meter Measurer

Distance Meter Measurer

The Central Importance of Measurement in Science

The mass of an object is a measure of the quantity of matter present in it and remains constant. The S. I. Unit of mass is the kilogram (Kg). The weight of an object varies with the gravitational field influencing it. While the S.I. Unit of length is the meter (m), length units on the atomic scale are nanometer (nm) and picometre (pm). Volume units are derived from length units, the most important volume units in Chemistry are the cubic meter (m3) and the liter (L). Density (d) is the ratio of mass to volume of a substance and is one of its characteristics physical properties. Temperature is a measure of relative hotness of an object. Heat is energy that flows from an object at higher temperature to one at lower temperature. Temperature scales differ in the size of the degree unit and/or zero point. In chemistry temperature is measured in Kelvin’s (k) or degrees Celsius (oC). Extensive properties, such as mass, volume and energy, depend on an objects size (extent). Intensive properties, such as density and temperature are independent of size. Nowadays measurement is so common that it is taken as for granted, but it has a long and fascinating history characterized by the search for exact, invariable standards.

 

System of measurement began thousands of years ago as trade, building and land surveying spread through the civilized world. For most of that time, however, measurements were based on inexact physical standards. For example: an inch was the length of three barley corns (seeds) placed end-to-end a yard was the distance from the tip of king Edgar’s nose to the tip of his thumb with his arm outstretched, and an acre was the area tilled by an man working with a pair of oxen in a day.

 

The standard meter is now based on two quantities, the speed of light in vacuum and the second. The history of the meter points up the ongoing drive to define units based unchanging standards. The French scientists who set up the metric system defined the meter as 1/10,000,000, the distance from the equator (through Paris) to the North Pole. The meter was later defined as the distance between the two five lines engraved on a corrosion resistant metal bar kept at the international Bureau of weights and Measures in France. Fear that the bar would be destroyed / damaged by war led to an exact, unchanging, universally available atomic standard, 1,650,763.73 wavelength of orange red light from electrically excited Krypton atoms. The current standard is even more reliable; 1 meter is the distance light travels in a vacuum in 1/299,792,458 second.

 

The U.S. copy of the master kilogram is kept in a vault at the National Institute of Standards and Technology near Washington, D.C. since 1889, it has been taken to France only twice for comparison with the master kilograms which is removed from its vault only once a year for such purposes. Two people are always present when it is moved, one to carry with forceps, the other to catch it, if the first person stumbles. The kilogram is unusual in another way; it is only base unit whose name has a prefix. Unlike the practice with other base units, however, we attach prefixes to the word “Gram” as in ‘microgram’ rather than to the word “kilogram”. Thus we never say “micro-kilogram”.

The S.I. Unit of time is the second(s). Although time was once measured by the day and year, it is now based in an atomic standard, microwave, and radiation from excited cesium atoms. In the laboratory, we study the speed of a reaction by measuring the time it takes a fixed amount of substance to undergo a chemical change. The range of reaction speeds is enormous a fast chemical change in over in a few nanoseconds (10-9s), whereas slow ones, such as rusting or biological aging, take years. Chemists use lasers to study changes that occur in a few picoseconds (10-12s) or even femto-seconds (10-15s). The accuracy of the best pendulum clock is to within 3 seconds per year and that of the best quartz clock is 1000 times greater. The latest version of the atomic clock, NIST-7, is over 2000 times more accurate still, to within 1 second in 6 million year. Rather than using the oscillations of a pendulum, the atomic clock measures the natural oscillation frequency of cesium atoms absorbing microwave radiations. 1 second is defined as 9,192,631,770 of these oscillations. Current plausto place an advanced laser-cooled cesium atomic clock on the international space station will allow longer observation times of the atoms, for atleast a 10 fold increase in accuracy.

 

About the Author

Dr.Badruddin Khan teaches Chemistry in the University of kashmir, Srinagar, india.

Ultrasonic Laser Point Pointer Distance Meter Measurer $24.99 Description:Press READ to turn on the unit, the laser point light on, the distance betwwen the laser distance measurer and the point you measured apears.To find the area and volume of a room, measure the length and press X/=,measure the width, then press X/=,then the square icon and the data of area appears, measure the height and press X/= the cubic icon and the data of volume appears.The initial unit is metric, hold the SET key 3 second, the unit can switch between METRIC and IMPERIAL.The laser distance meter turns itself off if no key is pressed within about 30 seconds.Size of the laser measurer: ~12.2 x 6 x 3.3cm(L*W*D)Weight: 117.3gSpecification:measurer power by 1 x 9V battery (will not be included here)Unit of measurement feet or meters.Accuracy 0.5%+1 digit(2-60ft)Working frequency 40KHzWorking temperature 32 degreeF to 109.4 degreeFRange 2 to 60 ft(0.55 to 18.288m)Specifications are typical: individual units might varySpecifications are subject to change and improvement without notice.Class II laser product output<1mw.Package included instruction manual.

DEWALT DW030P Laser Distance Measurer $119.99 Laser Distance Measurer - DW030P. Tool Pouch. Lanyard. (2) AAA Batteries

UltraSonic 50ft Digital Distance Measurer with Laser Guide $19 - Model: TD-501A- Measures distance from 1.3ft to 50ft (0.5m to 16m)- Calculation functions: area, addition- +/- 5% Accuracy- 0.8 inch Resolution (+/- 2cm of Measure precision and range would be affected under noisy, fast wind speed, temperature and moist environment)- LCD display- Foot/Meter modes (exchangeable between metric system and British system)- Built-in Laser Pointer Guidance- Automatically switch off after 30 seconds idle- Powered by 1 x 6F22 (9V) battery (sold separately)- User manual (English) includedSpecificationsDimensions: 5.43 in x 2.8 in x 1.69 inWeight: 6.95 oz

Bosch DLR130K Digital Distance Measurer Kit $100 Digital Distance Measurer Kit - DLR130K. Belt Pouch. (4) AAA Batteries

Factory Reconditioned Bosch DLR130K-RT Digital Distance Measurer Kit $69.99 Digital Distance Measurer Kit - DLR130K-RT. Belt Pouch

Mini UltraSonic 60ft Digital Distance Measurer with Laser Guide $17.9 - Measures distance from 1.5ft to 60ft- Calculation functions: area, volume, addition, subtraction- +/- 0.5 ~ 1% Accuracy- 0.5in Resolution- LCD display with Backlight- Foot/Meter modes- Built-in Guiding Laser Pointer

Bosch GLR825 820-ft Laser Distance Measurer $349.99 800-ft Laser Distance Measurer - GLR825. Hand Strap. Belt Pouch. (4) AAA Batteries

Bosch GLR500 500-ft Laser Distance Measurer $289.99 500-ft Laser Distance Measurer - GLR500. Hand Strap. Belt Pouch. (4) AAA Batteries

Bosch GLR225 230-ft Laser Distance Measurer $149.99 230-ft Laser Distance Measurer - GLR225. Hand Strap. Belt Pouch. (4) AAA Batteries

free shipping Ultrasonic Range Distance Finder Laser Point Measurer $19.51 FREE SHIPPING Ultrasonic Range Distance Finder Laser Point Measurer

Digital Ultrasonic Distance Measurer - Yellow $26.99 Function:Ultrasonic Distance Measurer ( acoustic wave used to measure distance)Such Digital Ultrasound Distance Measuring Tools have laser pointer to mark distance to pointMetric cm/m & Imperial Inch/Feet (You can convert a measurement between types)The measures range of this Yellow Digital Supersonic Distance Measurer is from 0.4m to 18mStore three different readingsCalculate the Area of 2 readingsCalculate the Volume of 3 readingsAccurate to 0.5%Feature:Such Ultrasonic Measurer has high quality and very high accuracy, very easy to useMulti Functions as listed aboveProfessional units used by Home handymen and Professional Builders, Anyone who may need to know exact distance measurements or room area or volume.Point the unit at the target shown by the laser press "Measure" and view the distance, it is that simpleTake 2 measurements and automatically calculate the AreaTake 3 measurements and automatically calculate the VolumeCan be used indoors and OutdoorsWater resistanceManual power on/off and auto power-offSpecification:Large Display: 35 x 18mm LCD display, with back light for reading in dark areas.Power: 1 x 9V alkaline requiredWeight: about 122gUnits size 135 x 70 x 38mmFull instruction booklet supplied

Lazer Distance Meter $131.99 LAZER DISTANCE METER

Robt. Bosch Tool Robt. Bosch Tool D16 Distance Measurer DLR130K $113.64 D16 distance measurer 4? pocket size laser distance measurer Measures length, area, and volume Continuous length mode 2 measuring reference points Ergonomic soft-grip area Measure up to 130', +/- 1/16? Brand #: Robt. Bosch Tool DLR130K UPC: 000346383362 Keywords: tape laser measurer level

Stabila Stabila Laser Distance Measurer 06300 $142.18 Laser distance measurer Range: Up to 100' with 1/16? accuracy throughout range Length, volume, square footage, continuous measure, Pythagorean Bright backlit screen Compact as a cell phone Uses 2 ?AAA?batteries Belt pouch included Brand #: Stabila 06300 UPC: 089634063001 Keywords: measuring tool electrnc laser measurer distance compact w belt pouch

Factory Reconditioned Bosch GLR225-RT 230-ft Laser Distance Measurer $99.99 230-ft Laser Distance Measurer - GLR225-RT. Hand Strap. Belt Pouch. (4) AAA Batteries

60ft Ultrasonic Tape Measurer With Laser Pointer $17.24 - Measures distance from 1.5ft to 60ft- Calculation functions: area, volume, addition, subtraction- +/- 0.5 ~ 1% Accuracy- 0.5in Resolution- LCD display with Backlight- Foot/Meter modes- Built-in Guiding Laser Pointer- Powered by 9V battery

Milwaukee 2280-20 Laser Distance Meter $199 Laser Distance Meter - 2280-20. (2) AAA Batteries

Dewalt Dewalt Laser Distance Measurer DW030P $147.9 Measuring range of 100??â„¢ with 1/8??Â? accuracy for fast and easy measurements Green back lit display for increased visibility on dark job sites One button, one function when selecting the unit to give volume, square ft., linear measurements as well as adds or subtract readings Continuous measurement for layout applications Flat base unit offers better stability when measuring from flat surface Brand #: Dewalt DW030P UPC: 885911142649

UT391 Laser Distance Meter $81.4 This laser distance meter is specially designed for users. It is high-precision and multi-functional.It can measure distance, area and volume, pythagorean laws can also be used to measure indirectly.This is light, easy to use and reliable.It provides accurate measurement easier and faster.This is usable in construction, upholster, property, traffic, fire-fighting, gardening, urban planning, water monitoring, electrical power overhaul and much more.Best replacement for traditional measuring instrument such as measuring tape.Specification:Measurement distance: Range: 0.1 m to 60m/Accuracy: positive/negative 1.5mm; Range 4 inches to 197 feet/Accuracy: positive/negative 0.06 inchesMeasurieng units: meter, inch, foot, 4 types unit displayArea, Volume calculations: Has m2/ft/m3/ft3 unitsIndirect measurement using Pythagoras: Supports 2.3 indirect measurementsAddition/Subtraction: YesContinuous measurement: YesMin/Max distance tracking: YesDisplay illumination and multi-line display: Maximum 4 displaysDatum option: Can choose front edge or end piece edge as datumBuzzer indication: YesBacklight display: White, can auto switch offAuto Bias Technology: Supports for external calibrationError indicator: Display error codeData hold: AutoHistory measurement records: 20Data clear: YesBattery indicator: High,Midium,LowLaser auto switch off: after 0.5 minAuto instrument switch off: after 3 minWaterproof: IP54Laser type: 635nm, less than 1mC Class IIBattery life: greater than 5000timesKey life: greater than 1 million timesOperating temperature: 0 to positive 40 degrees Celsius (positive 32 to 104 degrees Fahrenheit)Storage temperature: negative 10 to positive 60 degrees Celsius (positive 14 to positive 140 degrees Fahrenheit)Weight: 258gDimension: 122*43*28 mmPackage:1*UT391 Laser Distance Meter1*Carry bag1*Screwdriver1* Battery

Johnson 40-6005 230-ft Laser Distance Meter $189.99 230-ft Laser Distance Meter - 40-6005. (2) AA Alkaline Batteries. Safety Strap. Soft-Sided Pouch

Johnson 40-6004 130-ft Laser Distance Meter $129.99 130-ft Laser Distance Meter - 40-6004. 9V Alkaline Battery. Rubberized LDM Protection Cover. Safety Strap. Soft-Sided Pouch

Leica 763495 DISTO D2 Handheld Laser Distance Measurer (For Indoor Applications) $179 Holster. Hand Loop. (2) AAA Batteries. User's Manual

Bosch GLM80 265-ft Lithium-Ion Laser Distance Meter $179.99 265-ft Lithium-Ion Laser Distance Meter - GLM80. Micro USB Charger. Carrying Case. Pocket Guide (Quickstart Manual)

Bosch R60 24-in Measuring Rail for GLM80 Laser Distance Meter $100 24-in Measuring Rail for GLM80 Laser Distance Meter - R60. Carrying Case. Pocket Guide (Quickstart Manual

PD-56 Handheld Laser Distance Meter $129.3 Function:Addition Subtraction: Single distance, area, volume measurement all can be realized by using addition/subtraction to accumulate or regressivePythagorean: This is sued in the condition that the objective needing to be measure is covered or has no effective reflecting surface and cannot be measured directly. The accurate measured result can be got only when the laser beam and measured goal are at the right angle.AreaVolumeData storage and listTechnical specifications:Range ( for extended distance, use a target Plate): 0.05m to 60 mMeasuring accuracy: typically: positive/negative 1.5mmMinimum unit displayed: 1mmLaser class: IILaser type: 635nm, less than 1mWAutomatic power off: after 180sDisplay illumination: checkContinuous measurement: checkAddition/Subtraction: checkData storage capacity: 20Battery (AAA 2*1.5V): up to 5000 measurementsWeight: 447gDimension: 120*55*30 mmStorage temperature: negative 25 to positive 70COperation temperature: negative 10 to positive 50CIn unfavorable conditions, such as intensive sunshine, very weakly reflecting target surface or large temperature fluctuations, measuring accuracy may deteriorate.Maintenance: Do not immerse the instrument into water. You can use wet soft cloth to wipe the surface, but do not use corrosive lotion. Clean optical components like cleaning eyeglasses and camera lenses

Leica 776110 DISTO D210XT Handheld Laser Distance Meter $219 DISTO D210XT Handheld Laser Distance Meter - 776110. Holster. Hand Loop. (2) AAA Batteries. Quickstart Guide. Producer Inspection Certificate. Printed Safety Instructions. Manual - Safety Instructions On CD

Leica 776748 DISTO D330i Laser Distance Meter with BLUETOOTH Technology $379 DISTO D330i Laser Distance Meter with BLUETOOTH Technology - 776748. Holster. Hand Loop. (2) AAA Batteries. Quickstart Guide. Producer Inspection Certificate. Printed Safety Instructions. CD With Leica DISTO Transfer For PC And PPC, Autocad Plugin. Manual - Safety Instructions On CD