What is a Planimeter?
What is Planimeter?
A planimeter is a surveying tool used to measure the area of any plan. This instrument is most helpful for determining the area of irregular shapes that are difficult to measure without it. The planimeter is equipped with a wheel, lever, and counter that work together to measure the area of the plan.
How Does Planimeter Work?
The planimeter is used by tracing a plan drawn on a sheet with a wheel connected to a lever. The wheel rolls along the perimeter of the plan, and the lever is used to measure the length of the plan. The wheel and lever are connected to a counter, which records the total area of the plan. Once the wheel has gone around the entire perimeter of the plan, the counter displays the area of the plan.
Components of Planimeter
The main components of a planimeter are the wheel, lever, and counter. The wheel is used to trace the perimeter of the plan, while the lever measures the length of the plan. The counter records the area of the plan and displays the result.
Benefits of Using Planimeter
Planimeter is a useful tool for measuring the area of irregular shapes that are difficult to measure without it. It is also a time-saving device, as it eliminates the need to calculate the area by hand. Additionally, planimeters are accurate and reliable instruments and can be used to measure the area of a plan quickly and easily.
Parts of a Planimeter
Before we start with how to use planimeter, first let us know about the parts of a planimeter. Following are the parts of a planimeter:
- Tracing arm
- Tracing point
- Anchor arm
- Weight and needle point
- Clamp
- Hinge
- Tangent screw
- Index
- Wheel
- Dial
- Vernier
Tracing Arm
What is a Tracing Arm?
A tracing arm is an arm used to manage the position of a tracing point at one end. This is done by using a hinge to control the movement of the tracing point. The tracing arm is often used in industrial applications and can be used to accurately measure distances and angles.
Tracing Point
What is a Tracing Point?
A tracing point is a movable needle-like object that is connected to a tracing arm. This point is used to trace the outline of an area that needs to be measured. It is a precision tool used by surveyors and other professionals to accurately measure areas.
Anchor Arm
What is Anchor Arm?
Anchor arm is a tool used to maintain the accuracy of the anchor position and needle point location in a plan. It consists of two parts: one end is attached to the weight and needle point, while the other end is connected to the integrating unit. This device helps to ensure that the anchor point is securely and accurately placed.
How Anchor Arm Works?
Anchor arm works by connecting the weight and needle point to the integrating unit. The weight is secured to the anchor point, while the needle point is connected to the integrating unit. This helps to maintain the exact position of the anchor point and needle point in relation to the plan. The anchor arm also helps to prevent any movement of the anchor point or needle point, ensuring accuracy and precision in the placement of the anchor point and needle point.
Weight and Needle Point
What is a Plumb Bob?
A plumb bob is a tool used in surveying and construction to ensure that vertical lines are truly vertical. It is a weight, usually made of lead or steel, that is suspended from a string or cord and used to establish a vertical reference line. It is also referred to as an anchor, as the fine needle point at the base of the weight is secured to the required station on the plan.
How Does A Plumb Bob Work?
A plumb bob works by using gravity to pull the point of the bob towards the center of the Earth. This creates a vertical reference line that can be used to measure the true verticality of structures or to mark out a vertical line on a plan. The plumb bob is secured at the required station and allowed to hang freely, so that its point rests on the desired location. By accurately measuring the distance from the point of the bob to the station, a surveyor or builder can ensure that their lines are truly vertical.
Clamp
What is a Clamp?
A clamp is an instrument used for gripping or securing an object in place. It usually consists of two or more arms connected to a frame or handle, allowing for a firm grip and secure hold. Clamps are commonly used in a variety of applications, from carpentry to metalworking.
Uses of Clamps
Clamps are used to secure objects in place during various processes, such as soldering, welding, and cutting. They are also often used to hold things together while glue or other adhesives are used. In woodworking and carpentry, clamps are used to hold pieces of wood together while glue dries.
Clamps for Tracing Arms
Clamps are also often used to fix tracing arms in standard length without any extension. This allows the tracing arm to stay in place while the user traces a desired shape or design on the surface. Clamps are used to ensure that the tracing arm remains securely in place while the tracing task is being carried out.
Hinge
Connecting the Tracing Arm and Anchor Arm
The integrating unit is used to connect the tracing arm and anchor arm together with the help of a hinge. This hinge allows the arms to rotate around their axes. This mechanism makes it possible for the arms to move in a range of directions, thus allowing for more flexibility in operation.
Tangent Screw
What is a Tangent Screw?
A tangent screw is a mechanical device used to adjust the length of a tracing arm. It consists of a screw with a thread that is used to adjust the length of the tracing arm. The screw is connected to a handle that can be turned to extend or retract the length of the tracing arm. The tangent screw is a simple and effective way to adjust the length of the tracing arm to the required length.
Index
WHAT IS A MEASURING INDEX?
Measuring Index is a location that houses various measurement equipment such as wheels and dials. It is used to measure and monitor different measurements, allowing for accurate readings to be taken. The index helps to ensure that the readings are accurate and up-to-date.
Wheel
What is Wheel Fixed in the Integrating Unit?
A wheel fixed in the integrating unit is a component used to measure the tracing length. This wheel is used to calibrate the scale to set the zero point.
How Does the Wheel Fixed in the Integrating Unit Work?
The wheel fixed in the integrating unit works by providing a reference point for the tracing length. By rotating the wheel, the scale can be set to the zero point, allowing accurate readings of the tracing length.
Dial
What is a Dial?
A dial is a type of scale that is used to set the initial level to zero. It is usually adjusted using a setting wheel.
How to Use a Dial
Using a dial is relatively simple. To set the initial level to zero, simply use the setting wheel to adjust the dial. Once the desired level is achieved, the dial should be set to zero.
Vernier
What is Vernier?
A Vernier is a device that is attached to the wheel of a machine. It consists of a rounded drum with graduations on it, divided into 100 parts. This device is used to measure precise distances, angles, and other features.
How to Use Planimeter in Surveying?
Step 1: Fixing the Anchor Point
When using a planimeter to calculate the area of a given plan, the first step is to fix an anchor point. For a small plan, the anchor point is placed outside the plan. For a large plan, it is placed inside the plan.
Step 2: Placing the Tracing Point
Once the anchor point is fixed, the tracing point is placed on the outline of the given plan using the tracing arm. The initial reading A of the Vernier should be noted down after the tracing point is marked.
Step 3: Moving the Tracing Needle
The tracing needle should be moved carefully over the outline of the given plan in a clockwise direction until the first point is reached. After reaching the first point, the final reading B of the Vernier should be noted down.
Step 4: Calculating the Area of the Plan
The area of the plan which was traced by the planimeter can then be determined using the formula: Area = (B – A) x K, where K is the area constant of the planimeter.
Area = M (B – A + 10N + C)
- Explanation of Planimeter Terms
A planimeter is an instrument used for measuring the area of a two-dimensional shape. The planimeter consists of two constants, M and C, which are provided on the plan, and three variables, A, B and N. A is the initial reading, B is the final reading and N is the number of completed revolutions of the wheel during one complete tracing. N is positive if the dial passes the index in a clockwise direction, and N is negative if the dial rotates in an anticlockwise direction. - How to Calculate Area With a Planimeter
Area can be calculated by using a planimeter. The constants M and C are provided on the plan. The three variables, A, B and N, are used to determine the area. A is the initial reading, B is the final reading and N is the number of completed revolutions of the wheel during one complete tracing. N is positive if the dial passes the index in a clockwise direction, and N is negative if the dial rotates in an anticlockwise direction. Constant C is used only when the anchor point is placed inside the plan.