Natural Resources Canada’s (NRCan) Earth Sciences Sector (ESS) in Ottawa, ON possesses two scientific instruments that require servicing every 2 to 3 years. The highly specialized equipment measures the absolute gravity using free-fall approach in a vacuum. The equipment was purchased from - Micro-G Lacoste. The A10-003 was purchased and delivered in 2000 at the cost of $205,051.00 and the FG5-236 in 2007 at the cost of $354,715.00.
The A10 and FG5 allow researchers at NRCan to measure gravity down to the 8th decimal (9.81234787 m/s2) allowing to study of the exact shape of the Earth for accurate positioning, crustal deformation, mass density and mass redistribution, earthquake study, geophysics, geology, etc. Maintaining a national network of gravity stations with its temporal variation is part of the Division’s core activities.
The FG5-236 and A10-003 require a standard maintenance service (tune-up), which includes servicing the dropping chamber, interferometer base, superspring, electronics and computer system. Two main parts, which maintain vacuum in the dropping chamber, need to be replaced due to normal usage. The service includes a series of inspections, lubrication, cleaning, alignment, calibration, replacement of basic parts and test runs on a known calibrated base. Service and calibration of the instruments requires specialized expertise, diagnostic equipment and testing facilities in a controlled environment.
