Long-gauge axial extensometer that clamps on steel strand over a 500 mm gauge length for accurate elongation measurement in tensile tests.
Overview
This extensometer is a long-gauge, wide-range strain gauge purpose-built for tensile testing of prestressing steel strand. Measuring elongation from the relative crosshead displacement is cumbersome and inaccurate; instead, the instrument clamps two knife edges onto the strand over a 500 mm gauge length. As the strand stretches during a tensile test, the upper guide tube moves and a displacement transducer converts the mechanical displacement into an electrical signal. Together with a load cell and a computer it plots a P-L curve, allowing precise determination of the 0.2% proof force Fp0.2, maximum force Fm, total elongation Agt and Young's modulus E, throughout the test up to specimen fracture. Compliant with GB/T 5224, ISO 15630-3 and ASTM A416/A1061 for prestressing steel.
Applications
• Road and highway engineering laboratory testing
• Construction material quality control and acceptance
• Research and teaching laboratories
• Third-party inspection and certification bodies
Features
• High measurement accuracy with stable repeatability
• Robust construction suitable for both laboratory and field use
• Compliant with relevant Chinese and international testing standards
• Complete with calibration certificate and operation manual
Technical Specifications
| Item | Specification |
| Application | axial strain measurement on prestressing strand |
| Gauge length | 500 mm |
| Measuring range | 0–50 mm |
| Accuracy class | class D |
| Resolution | 0.01 mm |
| Excitation | 6–12 V |
| Sensitivity | ≥2 mV/V |
| Dimensions | approx. 500×65×45 mm |
| Protection | rugged, measures to fracture; upper/lower tubes separate automatically |
| Construction | upper/lower knife blocks, upper guide tube, lower sleeve, guide, displacement transducer |
| Fixing | rubber bands + hose clamps on the strand |
| Signal | strain-gauge displacement output, to indicator/DAQ |
| Measured | Fp0.2, Fm, Agt, E, etc. |
| Standards | GB/T 5224, ISO 15630-3, ASTM A416/A1061 |
Standards
GB/T, JTG, ASTM
Standard Delivery
• Main instrument unit
• Power cable
• Operation manual
• Spare parts kit
FAQ
Q1: What standards does the Axial Extensometer for Prestressing Steel Strand comply with?
A1: The Axial Extensometer for Prestressing Steel Strand is designed and manufactured in accordance with relevant Chinese national (GB) and transport industry (JTG) standards, as well as applicable ASTM and AASHTO international standards. A calibration certificate traceable to national standards is provided with each unit.
Q2: How often should the Axial Extensometer for Prestressing Steel Strand be calibrated?
A2: We recommend annual calibration by authorized technicians or by iRoad after-sales service center. For high-frequency laboratory use, semi-annual calibration is advised. The instrument is supplied with a factory calibration certificate.
Q3: What is the lead time and do you provide training?
A3: Standard units are usually shipped within 7-15 working days. Custom configurations may require 20-30 days. iRoad provides on-site installation, commissioning and operator training for major equipment; remote video guidance is available for standard laboratory instruments.
Overview
This extensometer is a long-gauge, wide-range strain gauge purpose-built for tensile testing of prestressing steel strand. Measuring elongation from the relative crosshead displacement is cumbersome and inaccurate; instead, the instrument clamps two knife edges onto the strand over a 500 mm gauge length. As the strand stretches during a tensile test, the upper guide tube moves and a displacement transducer converts the mechanical displacement into an electrical signal. Together with a load cell and a computer it plots a P-L curve, allowing precise determination of the 0.2% proof force Fp0.2, maximum force Fm, total elongation Agt and Young's modulus E, throughout the test up to specimen fracture. Compliant with GB/T 5224, ISO 15630-3 and ASTM A416/A1061 for prestressing steel.
Applications
• Road and highway engineering laboratory testing
• Construction material quality control and acceptance
• Research and teaching laboratories
• Third-party inspection and certification bodies
Features
• High measurement accuracy with stable repeatability
• Robust construction suitable for both laboratory and field use
• Compliant with relevant Chinese and international testing standards
• Complete with calibration certificate and operation manual
Technical Specifications
| Item | Specification |
| Application | axial strain measurement on prestressing strand |
| Gauge length | 500 mm |
| Measuring range | 0–50 mm |
| Accuracy class | class D |
| Resolution | 0.01 mm |
| Excitation | 6–12 V |
| Sensitivity | ≥2 mV/V |
| Dimensions | approx. 500×65×45 mm |
| Protection | rugged, measures to fracture; upper/lower tubes separate automatically |
| Construction | upper/lower knife blocks, upper guide tube, lower sleeve, guide, displacement transducer |
| Fixing | rubber bands + hose clamps on the strand |
| Signal | strain-gauge displacement output, to indicator/DAQ |
| Measured | Fp0.2, Fm, Agt, E, etc. |
| Standards | GB/T 5224, ISO 15630-3, ASTM A416/A1061 |
Standards
GB/T, JTG, ASTM
Standard Delivery
• Main instrument unit
• Power cable
• Operation manual
• Spare parts kit
FAQ
Q1: What standards does the Axial Extensometer for Prestressing Steel Strand comply with?
A1: The Axial Extensometer for Prestressing Steel Strand is designed and manufactured in accordance with relevant Chinese national (GB) and transport industry (JTG) standards, as well as applicable ASTM and AASHTO international standards. A calibration certificate traceable to national standards is provided with each unit.
Q2: How often should the Axial Extensometer for Prestressing Steel Strand be calibrated?
A2: We recommend annual calibration by authorized technicians or by iRoad after-sales service center. For high-frequency laboratory use, semi-annual calibration is advised. The instrument is supplied with a factory calibration certificate.
Q3: What is the lead time and do you provide training?
A3: Standard units are usually shipped within 7-15 working days. Custom configurations may require 20-30 days. iRoad provides on-site installation, commissioning and operator training for major equipment; remote video guidance is available for standard laboratory instruments.
