Checking/calibration frequencies

Item Calibration / check

Description Minimumfrequency

Calibrate Check/ Verify

Std form/Method

Vernier 2 years Approved external lab

Standard weights(this is an statutory requirement)

Every year Weight & measure deptt

Perforated steel sieves (aggregate) 1 year FT12

Working woven mesh sieves (sand) 1 year FT13

Master sieves - woven mesh 3 years Approved external lab

Flakiness gauge 1 year FT16

Elongation Gauge 1 year FT15

Density containers 1 year FT23

pH meter 1 year Approved external lab

Cube moulds 3 months FT5

Cube testing machine, loading rate 6 months Approved external lab

Slump cones / tamping rod 3 months FT4

Master thermometer 3 years Approved external lab

Working thermometer 1 year FT14

Square Gauge 1 years Approved external lab

Scale 1 year FT3 / External agency

Oven 1year External agency