NABL Accredited · NDT Service
Crack Depth & Width Test
(Ultrasonic Crack Depth Measurement)
Non-destructive measurement of concrete crack depth using ultrasonic pulse velocity method and crack width using optical crack gauges — essential for structural assessment and repair planning.
IS 13311
Standard
±5mm
Accuracy
24hr
Report TAT
NABL
Accredited
NABL Accredited Lab · ISO/IEC 17025:2017
Digital Reports via Autovity QLMS
Pan-India · 7 Lab Locations
Est. 2009 · 20,000+ Projects
Overview
What is the Crack Depth & Width Test?
The Crack Depth Test uses the BS EN indirect UPV method (TOFD — Time of Flight Diffraction) to measure the depth of surface cracks in concrete without drilling. The crack width is measured simultaneously using calibrated optical crack gauges. Both parameters are essential for structural assessment and repair specification.
Conducted as per IS 13311 and BS EN 12504-4, crack depth and width measurement is routinely required for post-earthquake inspection, aging structure assessment, insurance claims and pre-repair surveys. Global Lab measures crack depths up to 500mm and crack widths from 0.05mm using NABL-calibrated equipment.
Non-Destructive Depth Measurement
UPV TOFD method measures crack depth without drilling or coring.
Optical Crack Width Measurement
Calibrated optical gauges measure crack widths from 0.05mm to 5mm.
Crack Mapping
All cracks on structural element documented with location, width and depth map.
Structural Risk Assessment
Crack dimensions correlated with IS 456 acceptance criteria for risk classification.
NABL Certified Reports
All results on NABL-accredited letterhead with crack location and dimension maps.
Monitoring Capability
Crack width gauges can be installed for long-term monitoring of crack progression.
Test in Action
Crack Depth & Width Test — Site Images
Optical Crack Width Gauge Measurement
UPV Transducers Placed Either Side of Crack
Crack Map Prepared on Structural Element Sketch
Test Procedure
How the Crack Depth & Width Test is Conducted
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1Visual Crack IdentificationAll visible cracks on the structural element are identified and marked with their approximate location on a sketch.
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2Crack Width MeasurementCalibrated optical crack gauge (graticule type) is placed over each crack. Width is read at narrowest and widest points.
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3UPV Transducer Placement for DepthFor each crack, two UPV transducers are placed on either side of the crack at equal distances from the crack line.
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4TOFD MeasurementTransit time is measured for direct propagation (no crack) and compared with time when crack blocks the direct path to calculate crack depth.
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5Crack Map & Structural AssessmentAll cracks documented on element sketch with measured widths and depths. Risk classification per IS 456. NABL report within 24 hours.
Standards & Specifications
Applicable Test Standards
| Standard | Title | Scope | Type |
|---|---|---|---|
| IS 13311 Part 1 | Methods of Non-Destructive Testing of Concrete — UPV | Crack Depth | Indian Standard |
| BS EN 12504-4 | Testing Concrete — Determination of Ultrasonic Pulse Velocity | UPV Method | British Standard |
| IS 456:2000 | Plain and Reinforced Concrete — Code of Practice (Crack Width Limits) | Acceptance Criteria | Indian Standard |
| ACI 224R | Control of Cracking in Concrete Structures | Crack Assessment | ACI |
Applications
Where is the CAPO Test Used?
Post-earthquake inspection of RCC buildings and bridges
Aging structure assessment for insurance or legal compliance
Pre-repair survey to quantify crack severity before grouting or repair
Investigation of structures showing sudden increase in visible cracking
Commissioning inspection of new structures showing construction cracks
Periodic monitoring of known cracks for progressive deterioration
Why Choose Global Lab
Our Advantages
NABL Accredited ReportsLegally valid crack assessment certificates for insurance and legal proceedings.
Complete Crack DocumentationAll cracks documented with location, width, depth and structural risk rating.
Combined NDT PackageCrack depth + UPV + Rebound Hammer + Half-Cell as a complete structural audit.
Pan-India CoverageField engineers across 7 lab locations for rapid post-disaster deployment.
Fast TurnaroundOn-site results immediately; formal NABL report within 24 hours.
Monitoring SolutionsLong-term crack width monitors installed for progressive crack tracking.