Height of Instrument Calculator

✖Reduced level is the vertical distance between a survey point and the adopted level datum.ⓘ Reduced Level [RL]			+10% -10%
✖Back Sight is the sight or reading taken towards the back or towards a known elevation.ⓘ Back Sight [BS]			+10% -10%

✖Height of instrument is the vertical distance from the surface of earth to the collimation plane. It is also called as height of plane of collimation.ⓘ Height of Instrument [HI]

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Formula

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Height of Instrument

Formula

`"HI" = "RL"+"BS"`

Example

`"49m"="29m"+"20m"`

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Height of Instrument Solution

STEP 0: Pre-Calculation Summary

Formula Used

Height of Instrument = Reduced Level+Back Sight
HI = RL+BS
This formula uses 3 Variables

Variables Used

Height of Instrument - (Measured in Meter) - Height of instrument is the vertical distance from the surface of earth to the collimation plane. It is also called as height of plane of collimation.
Reduced Level - (Measured in Meter) - Reduced level is the vertical distance between a survey point and the adopted level datum.
Back Sight - (Measured in Meter) - Back Sight is the sight or reading taken towards the back or towards a known elevation.

STEP 1: Convert Input(s) to Base Unit

Reduced Level: 29 Meter --> 29 Meter No Conversion Required
Back Sight: 20 Meter --> 20 Meter No Conversion Required

STEP 2: Evaluate Formula

Substituting Input Values in Formula

HI = RL+BS --> 29+20

Evaluating ... ...

HI = 49

STEP 3: Convert Result to Output's Unit

49 Meter --> No Conversion Required

FINAL ANSWER

49 Meter <-- Height of Instrument

(Calculation completed in 00.020 seconds)

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Credits

Created by Chandana P Dev

NSS College of Engineering (NSSCE), Palakkad

Chandana P Dev has created this Calculator and 500+ more calculators!

Verified by Ishita Goyal

Meerut Institute of Engineering and Technology (MIET), Meerut

Ishita Goyal has verified this Calculator and 2600+ more calculators!

< 17 Levelling Calculators

Difference in Elevation between Two Points using Barometric Levelling

Go Distance between Points = 18336.6*(log10(Height of point A)-log10(Height of point B))*(1+(Temperature at Lower Ground Level+Temperature at Higher level)/500)

Difference in Elevation between Ground Points in short lines under Trigonometric levelling

Go Elevation Difference = Distance between Points*sin(Measured Angle)+Height of point A-Height of point B

Distance between Two points under Curvature and Refraction

Go Distance between Two Points = (2*Earth Radius in km*Error due to Curvature+(Error due to Curvature^2))^(1/2)

Distance for small errors under Curvature and Refraction

Go Distance between Two Points = sqrt(2*Earth Radius in km*Error due to Curvature)

Angle of Dip for Compass Surveying

Go Dip Angle = Distance between Two Points/Earth Radius in km*(180/pi)

Error Due to Curvature Effect

Go Error due to Curvature = Distance between Two Points^2/(2*Earth Radius in km)

Distance to Visible Horizon

Go Distance between Two Points = sqrt(Height of Observer/0.0673)

Permissible Closing Error for Rough Levelling

Go Closing Error = 100*sqrt(Distance between Two Points)

Permissible Closing Error for Ordinary Levelling

Go Closing Error = 24*sqrt(Distance between Two Points)

Permissible Closing Error for Accurate Levelling

Go Closing Error = 12*sqrt(Distance between Two Points)

Permissible Closing Error for Precise Levelling

Go Closing Error = 4*sqrt(Distance between Two Points)

Reduced Level given Height of Instrument

Go Reduced Level = Height of Instrument-Back Sight

Back Sight given Height of Instrument

Go Back Sight = Height of Instrument-Reduced Level

Height of Instrument

Go Height of Instrument = Reduced Level+Back Sight

Correction on Refraction Error

Go Refraction Correction = 0.0112*Distance between Two Points^2

Height of Observer

Go Height of Observer = 0.0673*Distance between Two Points^2

Combined Error Due to Curvature and Refraction

Go Combined Error = 0.0673*Distance between Two Points^2

Height of Instrument Formula

Height of Instrument = Reduced Level+Back Sight
HI = RL+BS

What is the Principle of Levelling?

The principle of levelling is to obtain horizontal line of sight with respect to which vertical distances of the points above or below this line of sight are found. 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 to Calculate Height of Instrument?

Height of Instrument calculator uses Height of Instrument = Reduced Level+Back Sight to calculate the Height of Instrument, The Height of Instrument is taken as the vertical distance of the instrument from the surface of earth. It is also taken as the height of the plane of collimation. Height of Instrument is denoted by HI symbol.

How to calculate Height of Instrument using this online calculator? To use this online calculator for Height of Instrument, enter Reduced Level (RL) & Back Sight (BS) and hit the calculate button. Here is how the Height of Instrument calculation can be explained with given input values -> 49 = 29+20.

FAQ

What is Height of Instrument?

The Height of Instrument is taken as the vertical distance of the instrument from the surface of earth. It is also taken as the height of the plane of collimation and is represented as HI = RL+BS or Height of Instrument = Reduced Level+Back Sight. Reduced level is the vertical distance between a survey point and the adopted level datum & Back Sight is the sight or reading taken towards the back or towards a known elevation.

How to calculate Height of Instrument?

The Height of Instrument is taken as the vertical distance of the instrument from the surface of earth. It is also taken as the height of the plane of collimation is calculated using Height of Instrument = Reduced Level+Back Sight. To calculate Height of Instrument, you need Reduced Level (RL) & Back Sight (BS). With our tool, you need to enter the respective value for Reduced Level & Back Sight and hit the calculate button. You can also select the units (if any) for Input(s) and the Output as well.

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