Difference between revisions of "AY Honors/Forestry/Answer Key"

Revision as of 22:27, 17 April 2008

The clinometer is a common tool used in forestry to measure slope, vertical angles, and -in combination with range measurements- elevation change or tree heights.

How It works

Clinometers, known in many fields as "inclinometers", make use of basic trigonometric principles. Multiplying the distance (D) between the observer and an object times the tangents of the angles to the base and to the top of the object, and then adding them together gives the observer the total height of the object.^&There are typically three different scales that can come on a clinometer: degrees, percent, and topo. When considering purchasing a clinometer it is important to be sure it is calibrated to units suitable for the intended use.

File:Illustration of the basic trigonometric principles used by a clinometer.JPG

Tree height measurement

Tree Height Measurement

The forester stands at a fixed distance from the base of the tree. The most common distances in the United States are 50, 66, and 100 feet. ^& To obtain accurate readings it is best to use taped measured distance instead of paced distances. For the most accurate readings it is best to use a distance that is equal to or greater than the height of the tree you are measuring. ^& The observer sites to the top of tree, if total height is the desired measurement. If merchantable height is the desired measurement the observer sites to a point on the tree where no more merchantable timber can be used. The observer then measures to the bottom of the tree and adds the two figures together. This will be the height of the tree. Always measure a leaning tree so that the tree is leaning to the left or right. Measurements should never be taken with the tree leaning toward or away from the observer because this will affect the accuracy of the measurement.

File:Measuring Slope With a Clinometer 2.JPG

Measuring slope with a clinometer

Slope Measurement

The clinometer is also commonly used by foresters to obtain the percent slope of terrain. This measurement is based on the same trigonometric principles described above. Slope measurements, however, require that both observer and target be a constant height above the ground; thus a range pole or height of measurement (HI) stick is often used in slope measurements.

A clinometer used in forestry

Manufacturers

Suunto

Haglöf

Brunton

Silva

Mrs. Swart

References

↑ Calvert, J.B. “The Clinometer.” 2003.
↑ Avery, T.E. and Burkhart, H.E. “Height Measurement Principles.” Forest Measurements 5th Edition. McGraw-Hill, 2002. 154.
↑ Williams, M.S., Bechtold, M.A., and V.J. LaBau. 1994 five instruments for measuring tree heights: an evaluation. Southern Journal of Applied Forestry 18: 76-82

@@ Line 1: / Line 1: @@
-[[Image:Stanley_compass_1.jpg|thumb|right|200px|Compass with inclinometer]]
+{{confusing|date=March 2008}}
-A  '''clinometer''' is an instrument for measuring angles of [[slope]] (or [[tilt]]), [[elevation]] or [[inclination]] of an object with respect to gravity. It is also known as a ''tilt meter'', ''tilt indicator'', ''slope alert'', ''slope gauge'', ''gradient meter'', ''gradiometer'', ''level gauge'', ''level meter'', ''declinometer'', and ''pitch & roll indicator''.
-Clinometers measure both inclines (positive slopes, as seen by an observer looking upwards) and declines (negative slopes, as seen by an observer looking downwards).
-==History==
-Early inclinometers include examples such as Well's inclinometer, the essential parts of which are a flat side, or base, on which it stands, and a hollow disk just half filled with some heavy liquid. The glass face of the disk is surrounded by a graduated scale that marks the angle at which the surface of the liquid stands, with reference to the flat base. The line 0.——0. being parallel to the base, when the liquid stands on that line, the flat side is horizontal; the line 90.——90. being perpendicular to the base, when the liquid stands on that line, the flat side is perpendicular or plumb. Intervening angles are marked, and, by the aid of simple conversion tables, the instrument indicates the rate of fall per set distance of horizontal measurement, and set distance of the sloping line.
-The earliest electronic inclinometers used a weight, an extension, and a [[potentiometer]]. Early in the 1900's (circa 1917) precision curved glass tubes filled with a damping liquid and steel ball were introduced to provide accurate visual angle indication. Common sensor technologies for electronic tilt sensors and inclinometers are [[accelerometer]], [[Liquid Capacitive Basics |liquid capacitive]], electrolytic, gas bubble in liquid, and pendulum.  Moving forward, [[MEMs]] (Micro-Electro-Mechanical Systems) technology is becoming the newest type due to their tiny size and low cost.
+The '''clinometer''' is a common tool used in [[forestry]] to measure [[slope]], [[vertical_(angles)|vertical angles]], and -in combination with range measurements- elevation change or tree heights.
-==Accuracy==
-Certain highly sensitive electronic inclinometer sensors can achieve an output accurate to .001 degrees. However, an inclinometer sensor's true or absolute accuracy (which is the combined total error) is a combination of initial sets of sensor zero offset and sensitivity, sensor linearity, hysteresis, repeatability, and the temperature drifts of zero and sensitivity - electronic inclinometers accuracy can typically range from .01º to ±2º depending on the sensor and situation. Typically in room ambient conditions the accuracy is limited to the sensor linearity specification.
+==How It works==
+Clinometers, known in many fields as "[[inclinometer]]s", make use of basic [[trigonometric]] principles. Multiplying the distance (D) between the observer and an object times the [[Trigonometric_functions_#Right_trianle_definitions|tangents]] of the angles to the base and to the top of the object, and then adding them together gives the observer the total height of the object.<ref>[http://mysite.du.edu/~jcalvert/astro/abney.htm Calvert, J.B. “The Clinometer.” 2003.]</ref>There are typically three different scales that can come on a clinometer: [[degrees]], [[percent]], and topo. When considering purchasing a clinometer it is important to be sure it is calibrated to units suitable for the intended use.
-[[Image:Well's Clinometer - Project Gutenberg eText 19465.png|thumb|The Well's clinometer]]
+[[Image:Illustration of the basic trigonometric principles used by a clinometer.JPG|right|thumb|Tree height measurement]]
-[[Image:Clinometerlow.jpg|thumb|A simple inclinometer]]
-==Sensor technology==
+==Tree Height Measurement==
+The [[forester]] stands at a fixed distance from the base of the [[tree]]. The most common distances in the [[United States]] are 50, 66, and 100 feet. <ref> Avery, T.E. and Burkhart, H.E. “Height Measurement Principles.” Forest
+Measurements 5th Edition. McGraw-Hill, 2002. 154.</ref> To obtain accurate readings it is best to use taped measured distance instead of paced distances. For the most accurate readings it is best to use a distance that is equal to or greater than the height of the tree you are measuring. <ref> Williams, M.S., Bechtold, M.A., and V.J. LaBau. 1994 five instruments for measuring tree heights: an evaluation. Southern Journal of Applied Forestry 18: 76-82</ref> The observer sites to the top of tree, if total height is the desired measurement. If merchantable height is the desired measurement the observer sites to a point on the tree where no more merchantable timber can be used. The observer then measures to the bottom of the tree and adds the two figures together. This will be the height of the tree. Always measure a leaning tree so that the tree is leaning to the left or right. Measurements should never be taken with the tree leaning toward or away from the observer because this will affect the [[accuracy]] of the measurement. [[Image:Measuring Slope With a Clinometer 2.JPG|right|thumb|Measuring slope with a clinometer]]
-[[Tilt sensor]]s and inclinometers generate an artificial horizon and measure angular tilt with respect to this horizon. They are used in cameras, aircraft flight controls, automobile security systems, and special switches.  Also used for platform leveling, boom angle indication, anywhere tilt requires measuring. Important specifications to consider when searching for tilt sensors and inclinometers are the tilt angle range and number of axes.  The tilt angle range is the range of desired linear output measured in degrees.  The number of axes the inclinometer and tilt sensor measure on is another important specification.
+==Slope Measurement==
+The clinometer is also commonly used by foresters to obtain the percent slope of terrain. This measurement is based on the same trigonometric principles described above. Slope measurements, however, require that both observer and target be a constant height above the ground; thus a range pole or height of measurement (HI) stick is often used in slope measurements.
-Common sensor technologies for tilt sensors and inclinometers are accelerometer, [[Liquid Capacitive Basics |Liquid Capacitive]], electrolytic, gas bubble in liquid, and pendulum.
+[[Image:Clinometer commonly used by foresters.JPG|right|thumb|A clinometer used in forestry]]
-Tilt sensor technology has also been implemented in video games.  ''[[Yoshi Topsy-Turvy]]'' and ''[[Kirby Tilt 'n' Tumble]]'' are both built around a tilt sensor mechanism, which is built into the cartridge.  The [[PlayStation 3]]'s game controller also utilizes tilt as a means to play video games.
-==Usages==
-Inclinometers are used for:
-* Determining the angle of the earth's magnetic field in respect to the horizontal plane.
-* Showing the inclination of an aircraft or ship relative to the horizontal. An [[fixed-wing aircraft|airplane]] instrument. See [[turn coordinator]] or [[slip indicator]][http://www.riekerinc.com/SlipIndicators.htm].
-* Showing a deviation from the true vertical or horizontal.
-* Surveying, in order to measure an angle of inclination or elevation.
-* Rollover warning, to alert equipment operator of possible tip over condition.[http://www.riekerinc.com/TiltIndicators.htm]
-* Measuring angles of elevation, slope, or incline, as of an embankment. Also called an inclinometer.
-* Measuring slight differences in slopes, particularly for [[geophysics]]. Such inclinometers are, for instance, used for monitoring [[volcano]]es, or for measuring the depth and rate of landslide movement.
-* Measuring movements in walls and/or the ground in civil engineering projects.[http://www.slopeindicator.com/instruments/inclin-intro.html]
-* Determining the dip of beds or strata, or the slope of an embankment or cutting; a kind of plumb level.
-* Some automotive [[safety]] systems.
-* Indicating pitch and roll of vehicles, sail boats, and aircraft.
-* Monitoring boom angle of cranes and material handlers.
-* Measuring the "look angle" of a satellite antenna towards a satellite.
-* Measuring the slope angle of a tape or chain during distance measurement.
-* Estimating the height of a building, tree, or other feature using a vertical angle and a distance (determined by taping or pacing).
-* Measuring the angle of drilling in well-logging applications.
-* Measuring the height of trees or other poles.
-* Measuring steepness of a ski slope. (<10 deg for beginners, 10-20 "green", 15-25 "blue", 25-35 "black", 35-45 "double black")
-* Measuring the orientation of [[plane (mathematics)|plane]]s and [[lineation]]s in rocks, in combination with a [[compass]]. (see [[structural geology]])
-=== Factors which influence usage ===
-(Overall accuracy varies depending on the type of inclinometer and technology utilized)
-* Gravity
-* Temperature (drift), zero offset, linearity, vibration, shock, cross-axis sensitivity, acceleration/deceleration
-* A clear line of sight between the user and the measured point is needed.
-* A well defined object is required to obtain the maximum precison.
-* The angle measurement precision and accuracy is limited to slightly better than one degree of arc.
-=== Survey methods ===
-* Inclinometers are used for the measurement of angles in reference to gravity.
-* The [[United States Department of Agriculture|USDA]] [[United States Forest Service|Forest Service]] uses inclinometers to measure tree height in its [[Forest Inventory and Analysis]] program.
 ==Manufacturers==
+Suunto
-* [http://www.leica-geosystems.com/corporate/en/ndef/lgs_33357.htm Leica Nivel200 two-axis precision inclination sensor]
+Haglöf
-* [http://www.soldata.co.uk Sol Data Limited - Instrumentation and Monitoring Specialist]
-* [http://www.gage-technique.com Gage Technique International - Geotechnical & Structural Instrumentation]
-* [http://www.soil.co.uk Soil Instruments (UK) Ltd - Geotechnical & Structural Instrumentation]
-* [http://pewa.panasonic.com/pcsd/product/sens/acce_sensor.html Panasonic Electric Works Corporation of America]
-* [http://www.riekerinc.com Rieker Incorporated]
-* [http://www.transportsupport.co.uk Transport Support - Vehicle Inclinometer Systems(A division of G.N.Systems Ltd)]
-* [http://www.measurandgeotechnical.com Measurand Inc - Unattended 3D Slope Monitoring]
-==See also==
+Brunton
-* [[Theodolite]]
+Silva
-* [[Clinometer (forestry)]]
-==External links==
+Mrs. Swart
-*[http://www.inclinometer.blogspot.com Inclinometer Blog - General Inclinometer Information]
-*[http://liftequipmentsafety.blogspot.com/ Safety Tips for Lift Equipment]
-*[http://www.transportsupport.co.uk Transport Support - Specialist Inclinometer manufactures for the transport industry (A division of G.N.Systems Ltd.)]
-[[Category:Dimensional instruments]]
+==References==
-[[Category:Inclinometers]]
+ <references/>
+==See Also==
+[[Inclinometer]]
-[[de:Klinometer]]
+[[Category:Forestry]]
-[[fr:Inclinomètre]]
-[[ja:クリノメーター]]
-[[no:Klinometer]]
-[[pt:Inclinômetro]]
-[[sl:Klinometer]]