Land Surveyor Forum

Routine Care of Surveying Equipment

Before making the first set-up of the day, visually inspect all surveying instrument for damage. You never know what might have happened the day before.  Check the machined surfaces and the polished faces of the lenses and mirrors. Try the clamps and motions for smooth operation (absence of binding or gritty sound).
Clean the exterior of the instrument frequently. Any accumulation of dirt and dust can scratch the machined or polished surfaces and cause friction or sticking in the motions. Remove dirt and dust with a clean, soft cloth or with a camel-hair brush. Clean non-optical parts with a soft cloth or clean chamois.
Clean the external surfaces of lenses with a fine lens brush and, if necessary, use a dry lens tissue. Do not use silicone-treated tissues because they can damage coated optics. The lens may be moistened before wiping it, but do not use liquids (oil, benzene, etc.) for cleaning. Do not loosen or attempt to clean the internal surfaces of any lens.
After an instrument has been used in damp or cold situations, use special precautions to prevent condensation of moisture inside the instrument. If the instrument is used in cold weather, leave it in the carrying case in the vehicle during non-working periods rather than take it into a heated room. If you store the instrument in a heated room overnight, remove it from the carrying case. If the instrument is wet or frost-covered, bring it into a warm, dry room, remove it from its case and leave it at room temperature to dry out.

Vehicle Transport

Transport and store instruments in positions that are consistent with the carrying case design. For example, total stations should be carried and stored in their correct position. Many instrument cases indicate the position in which they should be transported.
Treat tribrachs, prisms and tripods with care. Carry them in their shipping cases or cushion them with firm polyfoam or excelsior-filled cases to protect them from jolting or vibrating excessively.

Uncasing and Casing Instruments

Before removing an instrument, study the way it is placed and secured in the case. Place it in the same position when you return it to the case. In removing the instrument from the case, carefully grip it with both hands, but do not grip the vertical circle standard or where pressure will be exerted on tubular or circular level vials.

Setting Up an Instrument

Whenever possible, the instrument should be used in areas where operation is not dangerous to the instrument operator or the instrument. Select stable ground for the tripod feet. Do not set an instrument in front of or behind a vehicle or equipment that is likely to move.
In cold or hot weather when vehicle climate controls are used, survey instruments should be acclimated to outside conditions for an adequate period of time prior to final setup adjustments.
At the survey mark, firmly set the tripod with its legs spread wide. Push along the legs, not vertically downward. Extra precautions should be taken on smooth surfaces. The total station should not be attached to the tripod.
Always have the tripod firmly set before removing the instrument from its carrying case. Immediately secure the instrument to the tripod. If a total station is to be used, remove the instrument from the tribrach. Center and level the instrument over the mark using only the tribrach. Then place the total station in the tribrach for final leveling and verification that the instrument is still centered above the mark.
Never leave an instrument or its tribrach on the tripod without securing either to the tripod. Moderate pressure on the fastener screw is sufficient. Excessive tightening causes undue pressure on the foot screws and on the tribrach spring plate. Make sure the tribrach clamp is in the lock position.

Field Adjustments and Major Adjustments

Frequently check level vials, optical plummets, tripods, etc. for proper adjustment. In the field, make adjustments only when the instrument results are poor or require excessive manipulation.
Instruments should only be checked under favorable conditions. Only the adjustments described in the manual for the instrument should be made in the field or shop. Do not “field strip” (dismantle) instruments.
When an instrument has been damaged or otherwise requires major adjustments, contact the Construction Bureau. Indicate the type of repairs needed. In the case of total stations, digital levels or optical levels, describe the conditions under which the instrument does not function properly. Indicate if a “loaner” instrument is required.