calibration of 02 no of anchorage testing machine, 01 no of sound level meter, 03 no of alcohol tester, 03 no of personal dust sampler half yearly, 02 no of vane anemometer half yearly, 02 no of hygrometer half yearly and 01 no of sox & nox gas detector quarterly for one year in respect of churi colliery-sound level meter (no of instrument- 1) x (no of calibration on half yearly basis- 2) 2 anchorage testing machine(no of instrument- 2) x (no of calibration on half yearly basis- 2) 3 personal dust sampler [make- cassella] model-apex2 (no of instrument- 3) x (no of calibration on half yearly basis- 2) 4 vane anemometer [make- ota keiki seisakushu] (no of instrument- 2) x (no of calibration on half yearly basis- 2) 5 hygrometer (no of instrument- 2) x (no of calibration on half yearly basis- 2) 6 sox & nox gas detector (4 sensor) (no of instrument- 1) x (no of calibration on quarterly basis- 4) 7 alcohol tester (no of instrument- 3) x (no of calibration on half yearly basis- 2) 8 total impact of gst for the purpose of ctc