In surveying and linear measurement, five main types of materials used for measuring tapes are commonly used: linen tape, woven metallic tape, steel tape, synthetic tape, and invar tape. Each type differs in material, accuracy, durability, and suitable application scenarios.
- Measuring Tapes (Surveying Use)
A measuring tape is a flexible linear measuring tool used in surveying to measure distances on land or construction sites. - Primary Purpose
Used for linear measurements, including baseline measurement, topographical surveys, and general site measurement. - Key Differences Between Types
Measuring tapes differ mainly in:Material composition/Resistance to temperature and tension/Measurement accuracy/Application environment.
Types of Materials Used For Measuring Tapes (Comparison)
| Types of Materials Used For Measuring Tapes | |||||
| Type | Material | Typical Lengths | Advantages | Limitations | Common Use |
| Linen Tape | Woven linen with varnish | 10/20/30/50m | Lightweight, easy to handle | Shrinks when wet, elongates under tension | Basic surveying, rough measurements |
| Woven Metallic Tape | Linen reinforced with brass/copper wires | 2/10/15/30/50m | More durable than linen | Minor errors possible | Topographical surveys |
| Steel Tape | Steel or stainless steel | 1/3/5/7.5/8/10m | High accuracy, durable | Heavy, affected by temperature | Construction & surveying |
| Synthetic Tape | Glass fiber coated with PVC | 5/10/20/30/50m | Lightweight, non-conductive | Stretches under tension | Near electric fences, railways |
| Invar Tape | Nickel-steel alloy (36% Ni, 64% steel) | 20/30/50/100m | Extremely low thermal expansion | Expensive, delicate | High-precision surveying |
Detailed Explanation of Each Type
- Linen tape: also called cloth tape, is made of closely woven linen coated with varnish. It typically has a width of 12–16 mm and is supplied with metallic handles at both ends.
While lightweight and easy to use, linen tapes shrink when exposed to moisture and elongate when pulled, reducing accuracy. - Woven Metallic Tape:This tape improves on the linen tape by reinforcing it with brass or copper wires. A brass ring at the end is included in the tape length.It offers better durability and is commonly used in topographical surveys where minor measurement errors are acceptable.
- Steel Tape:Steel tapes are made from steel or stainless steel strips with widths ranging from 6 mm to 32 mm.
They feature clearly graduated meters, decimeters, and centimeters and are often housed in metal cases with automatic winding mechanisms, making them suitable for accurate surveying and construction work. - Synthetic Tape:Synthetic tapes are manufactured from glass fibers coated with PVC. They are lightweight, flexible, and non-conductive, making them safer near electric fences and railway lines.
However, they may stretch under tension, so they are not recommended for high-precision measurements. - Invar Tape:Synthetic tapes are manufactured from glass fibers coated with PVC. They are lightweight, flexible, and non-conductive, making them safer near electric fences and railway lines.
However, they may stretch under tension, so they are not recommended for high-precision measurements.
Final Summary
Different measuring tapes serve different surveying needs. Understanding the material properties, accuracy level, and application environment helps in selecting the right tape for reliable and efficient measurement.
FAQ
- What is the most accurate measuring tape for surveying? Invar tape is the most accurate because it is not affected by temperature changes.
- Why are steel tapes commonly used in construction? Steel tapes provide a good balance between accuracy, durability, and ease of use, making them ideal for construction sites.
- Are synthetic tapes suitable for precise measurements? No. Synthetic tapes may stretch under tension and are not suitable for high-precision surveying.
- Why do linen tapes lose accuracy? Linen tapes shrink when wet and elongate when pulled, which affects measurement reliability.