Moss, I.R.; Blick, G.H.; Wood, P.R. 1983 Surveying equipment and procedures for earth deformation studies : precise levelling. Lower Hutt: New Zealand Geological Survey. New Zealand Geological Survey report EDS 91 27 p.
Abstract: Precise levelling is undertaken by NZ Geological Survey to monitor vertical earth deformation at sites throughout New Zealand. This report details equipment and procedures up to June 1983. Equipment used includes three precise levels (Zeiss Nil, M.O.M. NiA31 and Zeiss Ni002), Zeiss invar staves (graduated to 5 mm and 10 mm) and a common design of change plates / spikes. Data collection has been in a field book or by utilising a HP19C programmable calculator. Benchmarks used, apart from those of outside organisations, are generally (a) a stainless steel pin set in a substantial block of concrete, (b) a stainless steel rod anchored to basement rock (or below permanent water table) protected by a freestanding galvanised iron pipe around it, or (c) a galvanised pipe anchored to basement, filled with concrete and with a stainless steel pin set in the top of it. Two forms of precise levelling are followed by NZGS. The first is the conventional leapfrog method between benchmarks and the second is (dry) tilt levelling. Procedures and specifications for methods of precise levelling are presented (auth)
