NABL Accredited · Dimensional Calibration
Elongation Gauge Calibration
(IS 2386 Part 1 — Aggregate Elongation Index)
NABL-accredited calibration of elongation gauges per IS 2386 Part 1 — verifying pin-to-pin spacing for each aggregate size fraction for accurate elongation index determination.
IS 2386 Pt.1
Standard
±0.1mm
Accuracy
1 Day
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 Elongation Gauge Calibration?
The Elongation Gauge has pins set at specified spacings for each aggregate size fraction — separating elongated particles (length > 1.8× mean sieve size). IS 2386 Part 1 specifies pin spacing per fraction from Table 2. Out-of-dimension gauges produce systematic EI errors.
At Global Lab, elongation gauge calibration verifies pin-to-pin spacing using calibrated Vernier calipers and slip gauges — comparing against IS 2386 Part 1 Table 2. Each pin-to-pin spacing reported individually on the NABL certificate.
Non-Destructive
Minimal surface preparation. Structure integrity is preserved throughout testing.
Fast Turnaround
On-site results within hours. Digital reports dispatched within 24 hours.
NABL Certified
All test and calibration results are backed by traceable measurements and standardized procedures.
Pan-India Coverage
Site engineers deployed across 7 lab locations and all major project sites.
Digital Reporting
Access reports anytime via Autovity QLMS client dashboard — zero paperwork.
High Accuracy
Results correlated to cube compressive strength with ±2% precision range.
Test in Action
Elongation Gauge Calibration — Site Images
Elongation Gauge Pin-to-Pin Spacing with Vernier
IS 2386 Table 2 Fraction Spacing Individually Verified
NABL Certificate — All Pin Spacings Certified
Test Procedure
How the Elongation Gauge Calibration is Conducted
-
1
Surface Preparation
A shallow groove (approx. 25mm deep) is cut into the concrete surface using a diamond-tipped cutting tool. The surface is cleaned of dust and debris. -
2
Insert Disc Placement
A specially designed steel insert disc is placed into the groove. A thin rod connects the disc to the pullout apparatus above the surface. -
3
Hydraulic Pullout Force Application
A hydraulic jack applies a steady, controlled pullout force to the insert disc via the reaction ring resting on the concrete surface. -
4
Failure Load Recording
The maximum force at which the concrete cone is extracted is recorded. A digital load indicator provides real-time readings with data logging. -
5
Strength Calculation & Reporting
The pullout force is correlated to cube compressive strength using established calibration curves. NABL-accredited reports are issued via Autovity QLMS.
Standards & Specifications
Applicable Test Standards
| Standard | Title | Scope | Type |
|---|---|---|---|
| IS 2386 Part 1 | Methods of Test for Aggregates — Particle Size and Shape | Elongation Test | Indian Standard |
| IS 2984 | Gauge Blocks | Reference Standard | Indian Standard |
| IS 3651 | Vernier Calipers | Reference Instrument | Indian Standard |
| NABL-141 | NABL Policy on Metrological Traceability | Traceability | NABL |
Applications
Where is the Elongation Gauge Calibration Used?
Annual elongation gauge calibration for NABL aggregate lab
NHAI MORTH road aggregate EI specification calibration
Quarry QA/QC elongation gauge calibration
Combined flakiness and elongation package
Pre-NABL assessment for aggregate scope
EI results dispute investigation
Why Choose Global Lab
Our Advantages
NABL Accredited CertificatesIS 2386 Part 1 elongation gauge certificates for NABL assessment.
Every Pin PairEach size fraction individually measured and certified.
Combined FlakinessElongation + Flakiness in one visit — efficient.
Fast 1-Day CertificateCertificate within 1 working day.
Pan-India CoverageDimensional calibration at all 7 locations.
Aggregate PackageElongation + Flakiness + Sieve together.