Hultafors Tools 2020 1
CCURACY are initially calibrated for their total
length. However, additional sections of the tape can be calibrated to determine the exact error of any length of the tape, according to the requirements of individual customers. CHECK YOUR TAPES PRECISION Steel Tape Measurement Accuracy Measurement accuracy is a very important feature of a tape measure. It is measured and stated in the form of a tolerance class. We classify measuring tapes in EC Class I and EC Class II. Steel Tape Measure Production Tolerances Total length (m) 2 Class I (mm) ±0.3 3 5 8 10 15 20 25 30 50 100 ±0.4 ±0.6 ±0.9 ±1.1 ±1.6 ±2.1 ±2.6 ±3.1 ±5.1 ±10.1 Accuracy tolerance excluding end hook. If the hook or ring forms part of the measurement an additional allowance of ± 0.1mm (Class I) 0.2mm (Class II) is permitted. Changing Lengths Often we experience significant temperature differences between summer and winter, differences that affect length of a steel tape measure. All tolerances quoted here apply at 20˚C, so it is important to be aware of the measurement deviations for various temperatures. Length Change for a Steel Tape Measure for Temperature Deviations from 20˚C ΔT 10˚C Length (m) 2 3 5 8 10 20 30 50 100 0.2 0.4 06. 1.0 1.2 2.5 3.7 6.2 20˚C 0.7 1.2 2.0 2.5 5.0 7.4 12.4 12.4 24.8 30˚C Length Change (±mm) 0.5 0.7 1.1 1.9 3.0 3.7 7.4 11.2 18.6 37.2 Length change ΔL DL is calculated using formula ΔL = L x ΔT x α L = tape measure length, ΔT = temperature difference from 20°C. α = coefficient of linear expansion (1.24 x 10-5). Example: If the outdoor temperature is -10°C the difference is -30°C, and the change will thereby be -3.0mm for an 8m long steel tape. 23 Class II (mm) ±0.7 ±0.9 ±1.3 ±1.9 ±2.3 ±3.3 ±4.3 ±5.3 ±6.3 ±10.3 ±20.3 BLADE VARIATIONS SHORT TAPES Matt Coat Carbon spring steel, hardened, tempered and concaved to enable long extension. Polyester coated for improved abrasive resistance. LONG TAPES Matt Coat Tough, white polyester coated steel tape. Printing is protected by an additional transparent polyester top coating. Resistant to commonly used solvents and abrasion. Tapes are accurate within the accuracy class marked on the tape, at a reference temperature of 20°C, when a tractive force of 50N is applied. This applies at all lengths to be measured. Tough Coat Tough, yellow polyester coated steel tape, with an extra thick nylon coating for added protection. Resistant to common chemicals, solvents, abrasion and breakage. Withstands bending, kinking and crushing. Recommended for heavy duty measuring work. Tapes are accurate within the accuracy class marked on the tape, at a reference temperature of 20°C, when a tractive force of 50N is applied. This applies at all lengths to be measured. Fibreglass Highly flexible tape, much lighter than steel. Constructed from multiple uni-directional glass-fibre strands embedded in flexible PVC. The tape also incorporates an extra thick PVC coating to offer superior resistance to scuffing and marking. Fibreflex tape is electronically nonconductive when dry, corrosion proof and resistant to breakage and common chemicals. Tapes are accurate within the accuracy class marked on the tape, at a reference temperature of 20°C, when a tractive force of 20N is applied. This applies at all lengths to be measured.