QC is based on measurements as it concerned with practical means. Metrology is an important tool of quality assurance.

Bigger size, high cost and effect of temperature and vibration on wavelength, se are disadvantages of laser.

It has two holes at ends in which gold plugs are inserted. Plugs have 2 lines longitudinally and 3 transversally and lines are in a neutral plane.

Slip gauges are used as end standards. When slip gauges are used in combination with end bars, re range of measurement is up to 1200 mm.

A quantitative management is a management representative, responsible for resolving all matters pertaining to quality and independent of or functions.

Nodal point for national measurement system is NPL and located in New Delhi. It has responsibilities like development and management of national standards, evaluation of measuring techniques etc.

A positive air pressure of about 10 to 20 N/m² relative to outside area is recommended in labs. Electrostatic precipitators are used to collect and attract dust particles, for this purpose y can be placed in corners.

Thermal error index can be reduced by establishing a more accurate coefficient of expansion, making corrections for NDE, minimizing temperature variation from 20 degree C.

Metre bar is supported by 2 rollers of diameter not less than 1 cm diameter. They are symmetrically placed in a same horizontal plane at a distance of 751 mm.

If used in a hot cathode discharge lamp n It is most suitable element. Temperature should be maintained at 64^oK.