SECTION 5 - MEASUREMENTS

5.1 Measurements

Surveying consists largely of determining the measurements of parcels of land. The reliability of the measurements depends on the equipment and techniques employed in measuring.

Measuring Equipment
Type
Field equipment should be chosen on the basis of its appropriateness to a given task.
Office (i.e. calculating and drafting) equipment should be integrated with field equipment.
Maintenance
Condition: All field equipment shall be kept in such working order as to achieve the precision normally expected of the equipment.
Placement: Precaution should be taken to avoid unexpected damage to the equipment in actual use, as well as in transport and in storage.
Measuring Techniques
Field
Human Errors: Sufficient redundant measurements shall be made to detect blunders and oversights.
Instrument Errors: Repeat measurements and proper corrections to measurements shall be made to minimize systematic errors.
Office
Random Errors: Judgment shall be exercised regarding
the need for, and
the proper method of adjusting measurements for random errors.
Record Keeping: Collected and processed data should be
in durable form,
stored safely, and
retrievable upon demand.
Commentary:

5.1(a)(1) Three types of equipment are meant: (1) transiting theodolite and steel tape, (2) repeating theodolite with electronic distance measuring device, or total station with data collector, and (3) global positioning system receivers.

5.1(a)(1)(A) The use of a particular type of instrumentation may be a business decision, based either on availability or on efficiency, rather than suitability and common use.

5.1(a)(1)(B) This rule may seem superfluous. Data collectors are useless without the appropriate computer hardware and software. But drafting still need not be aided by computer.

5.1(a)(2)(A) Theodolites, for instance, should be serviced according to the manufacturer’s specifications, and their precision checked periodically against a base line. Failure to detect an error in measurement, resulting either from poor care or poor use of equipment, is prima facie evidence of a violation of this section.

5.1(b) The techniques in question are those of plane surveying, rather than curvilinear or geodetic surveying. If ties of parcels of land to geodetic monuments are required, the land surveyor is expected to know the principles and techniques of geodetic surveying (see Section 9).

5.1(b)(2)(a)(ii) The proper method for adjusting measurements depends on the type and size of the survey. Small lot surveys may not require any adjustment. For larger surveys, one of the traditional adjustments (transit rule, compass rule or Crandall method) may be employed. For geodetic surveys, least squares adjustments are appropriate.

5.1(b)(3)(B) Keeping detailed records is not a statutory requirement, but it is a time-honored tradition, and a service to oneself and to the profession.

SURVEYING AND GEOMATERY



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