TY  - JOUR
AU  - Kohmun, Kanokporn 
AU  - Limsuwan, Pichet 
AU  - Ranusawud, Monludee 
AU  - Buranasiri, Prathan 
PY  - 2020
TI  - Length Measurement of Long Gauge Blocks by Interferometer
JF  - American Journal of Applied Sciences
VL  - 17
IS  - 1
DO  - 10.3844/ajassp.2020.196.203
UR  - https://thescipub.com/abstract/ajassp.2020.196.203
AB  - A gauge block interferometer with a vacuum chamber was designed and constructed for the measurement of gauge block lengths between 10 to 1,000 mm. In the chamber, four gauge blocks under the length measurement can be mounted on the measuring table. Furthermore, the length of all four gauge blocks can be measured continuously in one measurement. In this study, four gauge blocks with the nominal length of 125, 200, 400 and 500 mm were used for the length measurement. The environment parameters in the vacuum chamber including temperature, pressure, relative humidity and CO2 concentration were measured. The refractive index of air which depends on environment parameters was determined by using updated Edlén equation. Then, the lengths of four gauge blocks were measured and found to be 125.00025, 200.00019, 400.00070 and 500.00064, respectively.