LimsPulse
Construction materials testing

California Bearing Ratio (CBR) Test Apparatus

A load frame that pushes a 50 mm plunger into a compacted soil specimen at 1.25 mm/min and compares the load needed with that for a standard crushed stone. The ratio (CBR) is used to design road and pavement thickness.

  • Road and highway construction
  • Geotechnical testing
  • Airports and railways
  • Construction materials testing
  • Academic labs
Illustration of California Bearing Ratio (CBR) Test Apparatus
CALIBRATION

CBR apparatus calibration procedures

Load ring and penetration rate verification

Confirms that the proving ring (or load cell) reads load correctly against a traceable reference, and that the load frame drives the plunger at 1.25 mm/min.

Open procedure
QUALIFICATION

Instrument qualification (DQ · IQ · OQ · PQ)

  1. 01

    DQ — Design qualification

    Specifies frame capacity, penetration rate (1.25 mm/min), ring or load-cell range, plunger and mould dimensions to IS 2720 Part 16 / ASTM D1883.

  2. 02

    IQ — Installation qualification

    Checks frame installation, electrical safety, and records serial numbers and calibration certificates of ring and gauges.

  3. 03

    OQ — Operational qualification

    Verifies load measurement against a reference, penetration rate, and plunger and mould dimensions.

  4. 04

    PQ — Performance qualification

    Tests a reference soil or takes part in proficiency testing and checks agreement over time.

In LimsPulse · Calibration Management

Keep every CBR apparatus in control: usage logs, calibration and maintenance schedules, and automatic blocking of overdue instruments.

See how