ISO 12857-2-1997 PDF

Full title and description

ISO 12857-2:1997 — Optics and optical instruments — Geodetic instruments — Field procedures for determining accuracy — Part 2: Theodolites. This international standard specifies in‑situ field test procedures and observation sequences for determining and assessing the accuracy (precision/repeatability) of theodolites used in surveying and construction measurements.

Abstract

Provides practical field methods for verifying the performance of theodolites without recourse to specialized laboratory equipment. Procedures cover target and test‑setup geometry, observation sequences (including face positions and circle indexing), series of measurements and basic calculation of repeatability/standard deviation to characterise instrument accuracy in typical working conditions. The part was intended as an operational field verification method rather than a full acceptance or laboratory performance test.

General information

• Status: Withdrawn (withdrawal completed 13 December 2001; replaced by ISO 17123-3:2001).
• Publication date: 21 August 1997 (Publication: 1997-08-21).
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 17.180.30 — Optical measuring instruments.
• Edition / version: Edition 1 (1997).
• Number of pages: 25.

Scope

Specifies field procedures to be used when determining and evaluating the accuracy (repeatability and related error terms) of theodolites and their ancillary equipment. The scope covers configuration of test targets and lines of sight, recommended observation sequences (including use of two face positions), methods for measuring horizontal directions and vertical angles, and guidance to reduce atmospheric and environmental influences on results. The procedures are aimed at practical in‑situ verification rather than exhaustive laboratory characterization.

Key topics and requirements

• Test configuration and target geometry for theodolite checks (recommended layouts for multiple targets and sighting distances).
• Observation sequences: face I/II measurements, sets and series, graduated circle indexing or equivalent for electronic instruments.
• Procedures for measuring horizontal directions and vertical angles and for detecting collimation and axis errors.
• Statistical treatment of repeated observations (calculation of mean values, standard deviation and repeatability estimates).
• Guidance on environmental considerations (weather, atmospheric effects) and selection of suitable test conditions.
• Reporting conventions to document test configuration, results and basic uncertainty indicators for field verifications.

Typical use and users

Used by surveying and geodetic professionals, instrument technicians, calibration laboratories, manufacturers and quality managers who need a standardised field method to verify a theodolite’s suitability for site tasks. Typical applications include periodic field checks, pre‑use verification before critical surveys, and verification following transport, repair or adjustment of instruments.

Related standards

ISO 12857 is a multi‑part series; related parts and successors include ISO 12857-1:1997 (Levels) and ISO 12857-3:1997 (Electro‑optical distance meters). The ISO 12857 series was superseded and consolidated into the ISO 17123 series of field procedures (for example ISO 17123-3:2001 for theodolites and other ISO 17123 parts for levels and EDMs).

Keywords

theodolite, field procedures, geodetic instruments, accuracy, repeatability, collimation, horizontal angle, vertical angle, field verification, ISO 12857, ISO 17123

FAQ

Q: What is this standard?

A: ISO 12857-2:1997 is an international standard that specified field procedures for determining the accuracy of theodolites (practical in‑situ tests and observation sequences to assess instrument precision).

Q: What does it cover?

A: It covers test layouts, observation sequences (including face positions), measurement of horizontal and vertical angles, basic statistical evaluation of repeated observations and recommendations to minimise environmental effects during field checks.

Q: Who typically uses it?

A: Surveyors, instrument technicians, calibration and metrology laboratories, equipment manufacturers and quality managers who perform field verifications of theodolite performance.

Q: Is it current or superseded?

A: ISO 12857-2:1997 has been withdrawn (withdrawal recorded 13 December 2001) and its field procedures for theodolites were superseded by ISO 17123-3:2001 (ISO 17123 is the current consolidated series for field test procedures). Users should refer to ISO 17123-3 (and any later confirmations or revisions) for the current accepted procedures.

Q: Is it part of a series?

A: Yes — ISO 12857 was published in multiple parts addressing different geodetic instruments (parts for levels, theodolites and EDMs). These parts were later consolidated into the ISO 17123 series of field procedures.

Q: What are the key keywords?

A: Theodolite, field test, accuracy, repeatability, collimation error, horizontal angles, vertical angles, field verification, geodetic instruments, ISO 12857, ISO 17123.