30m Open Reel Steel Tape Measure

Best 30m tape measure surveyor tool for sales, made of high quality steel, ergonomic designed handle, comfortable grip, easy to hold. Small steel tape measure measuring tool applicable to surveying, road, railway, electricity, construction and other long-distance measurement.

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Dimension

Details

Tips: How to correct measurement error of steel tape measure?

There are three main factors that affect the measurement accuracy of steel tapes: Temperature, tension of the tape, and errors caused by the gravity of the tape when the steel tape measure is suspended in the air. The error correction methods caused by these three factors are as follows:

1. Temperature

• Prerequisite: There is no error when the tape is at 20℃.
• Calculation formula: Error due to temperature = actual measured value × scale tape expansion coefficient × (using temperature -20°C). For example: The expansion coefficient of a  steel tape measure is 0.0000115, and the error correction at 36m at the temperature of 10℃: 36000mm × 0.0000115 × (10 - 20) = -4.14mm.

2. The tension of the tape

• Prerequisite: The tape does not need to be corrected under standard tension. When the steel tape measure exceeds or falls below the standard tension, it will stretch.
• Calculation formula: Error due to tension = (actual measured tension - standard tension) × actual measured distance ÷ (stretch elastic force × cross - sectional area of the steel tape measure). Such as: Standard tension of 50N, correction at 36m under 100N tension: (100 - 50) × 36000mm ÷ (205800 × 2.52) = 3.47mm.

3. When the tape is suspended in the air for measurement, the error caused by the gravity of the tape.

• Calculation formula: The error caused by the gravity of the tape = {(unit weight of the tape × measured distance) × measured distance} ÷ (24 × tension when measured). For example, when 100N, 36m: {(0.000194 × 36000mm) × 36000mm} ÷ (24 × measured tension) = -7.32mm.

The correction parameters differ from steel tapes of different specifications.