Table of Contents
What is the procedure of Levelling?
Levelling is a process of determining the height of one level relative to another. It is used in surveying to establish the elevation of a point relative to a datum, or to establish a point at a given elevation relative to a datum.
How do you measure leveling?
Measuring the height of ground points Differences in height between two points are usually measured with a device called a level . It is called a level because it gives a true horizontal line . The height of each point is then measured by its vertical distance above or below this horizontal line.
What is leveling easy?
• Levelling or leveling is a branch of surveying, the object of which is to establish or. verify or measure the height of specified points relative to a datum. • It is widely used in cartography to measure geodetic height, and in construction. to measure height differences of construction artifacts.
How do you calculate RL levels?
Once you have taken all the levels you want, you will need to calculate the actual height values, or reduced levels (RL) by subtracting each one from the instrument height (IH). This gives you the ‘real’ height of the ground at the base of the staff.
How do I level my auto level?
An Auto Level is a level with a compensator. Setup your tripod as level as possible, step on tripod legs to drive into the ground. Attach auto level to the tripod. Adjust level so bubble is centered in vial. Adjust recital until crosshairs are clear. Adjust the objective lens until object you are sighting on is clear.
How do you calculate auto level distance?
With the Stadia Surveying Instrument i.e Aotolevel Machine focused on the rod, read the measurement markings on the stadia rod shown between the two stadia markings. Now convert the 0.36 meter into cm i.e, 0.36 x 100 = 36 cm. So, we can say The horizontal distance is 36 meter.
How is Auto Level level calculated?
In what way to compute the straight length (distance) through auto level machine at building place Set the tripod to the optimum position; tread on tripod limbs to meet the base. Attach auto level to the tripod. Change point to put the bubble in middle in case (vial). Change recital until crosshairs are visible.
What is double run leveling?
Leveling measurements for a double-run spur traverse are made in the forward direction from the origin to the destination and are then retraced along the same leveling route in the backward direction, from the destination to the origin. Every control point in a double-run spur traverse is occupied twice.
How many types of leveling are there?
Reciprocal leveling : Along a river or pond. Two level simultaneously used, one at either end. The fly leveling is done at the end of day’s work starting point on that particular day si known as check leveling. (II) Indirect or Trigonometric Leveling : By measuring vertical angles and horizontal distance; Less precise.
What is BS and FS in surveying?
h) Back sight : (B.S.) – The first sight taken on a levelling staff held at a point of known elevation. B.S. enables the surveyor to obtain HI +sight i.e. Height of Instrument or line of sight. i) Fore Sight : (F.S.) – It is the last staff reading taken from a setting of the level. It is also termed as minus sight.
What is Rise and Fall method?
Introduction. The rise and fall method is the method of calculating the difference in elevation between consecutive points in levelling work. Some of the points you have to know before starting numerical are: Back sights: The first reading after seeing the instrument is called back sights.
Why is it called a dumpy level?
In 1832, English civil engineer and inventor William Gravatt, who was commissioned to examine a scheme for the South Eastern Railway’s route from London to Dover, became frustrated with the slow and cumbersome operation of the “Y” level during the survey work, and devised the more transportable, easier-to-use “dumpy”.
What is auto Levelling?
A dumpy level, builder’s auto level, leveling instrument, or automatic level is an optical instrument used to establish or verify points in the same horizontal plane. It is used in surveying and building with a vertical staff to measure height differences and to transfer, measure and set heights.
How do you use a damp level?
Connect your device to the tripod and position it over 2 leveling screws. Screw your dumpy level onto the tripod’s base plate, then connect the base plate to the main tripod body. Once the instrument is securely attached, turn the dumpy level’s telescope so that it sits parallel with 2 of the device’s leveling screws.
How do you use auto level?
Auto Level Setup Setup your tripod as level as possible, step on tripod legs to drive into the ground. Attach auto level to the tripod. Adjust level so bubble is centred in vial. Adjust recital until cross-hairs are clear. Adjust the objective lens until object you are sighting on is clear.
How do you calculate RL by HI method?
Height of instrument method [hi]. ∑BS(a)−∑IS(b) = 1.36 -1.19 = 0.170 ( Rise of b ) RL(b) = RL(a) + Rise (b)= 50.00 + .170 = 50.17 ∑IS(h) −∑FS(i) =0.415 – 1.085 = – 0.67 ( Fall of i ) RL(i) = RL(h) – Fall(i) = 50.945 – 1.085 = 50.275.
What is the range of auto level?
Specifications of Sokkia B20 / B30/ B40 Automatic Level TELESCOPE Sokkia B20 Level Sokkia B40 Level Setting Accuracy 0.3 in. 0.5 in. Working Range ±15 ft. ±15 ft. CIRCULAR LEVEL Sokkia B20 Sokkia B40 Sensitivity 10 ft./2mm 10 ft./2mm.
