ISO 2975-1-1974 rus PDF

Full title and description

St ISO 2975-1:1974 — Measurement of water flow in closed conduits — Tracer methods — Part 1: General. Describes the general principles and selection criteria for tracer methods used to measure water flow in closed conduits, including choice of method and tracer, required mixing distance and sources of error.

Abstract

Tracer methods apply to flow measurement in conduits into which a tracer solution can be injected and where effective mixing with the flowing water can be achieved. The standard covers the main tracer procedures (constant-rate injection, integration/sudden injection and mean transit-time methods), guidance on tracer selection (radioactive and non‑radioactive options), determination of measuring and mixing lengths, and discussion of typical errors and achievable accuracy.

General information

• Status: Published (International Standard; confirmed in latest ISO review).
• Publication date: May 1974 (Edition 1, 1974-05).
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 17.120.10 (Flow in closed conduits).
• Edition / version: Edition 1 (1974).
• Number of pages: 11 pages.

Information above is taken from the ISO bibliographic record for ISO 2975-1:1974.

Scope

This part of ISO 2975 gives general guidance on the application of tracer techniques to measure the flow of water in closed conduits. It applies where a tracer solution can be injected and effectively mixed with the conduit flow. The standard explains the three principal procedures (constant-rate injection, sudden/integrated injection and mean transit-time), sets out considerations for choosing tracers (radioactive and non-radioactive), describes how to select measuring and mixing lengths and discusses error sources and accuracy expectations (errors can be less than 1% under good conditions).

Key topics and requirements

• Overview of tracer techniques suitable for closed conduits (dilution-based methods and transit-time methods).
• Descriptions of the three fundamental procedures: constant-rate injection, integration/sudden injection, and mean transit-time (Allen) method.
• Guidance on selection of tracers (non‑radioactive and radioactive) appropriate to site conditions and detection methods.
• Determination of adequate mixing distance and measuring length to ensure representative concentration or transit-time readings.
• Identification and assessment of main error sources and practical accuracy expectations (under favourable conditions, errors may be below ~1%).
• Notes on field implementation, sampling/detection considerations and limitations (applies to water; other liquids/gases covered in other documents).

Typical use and users

Used by hydraulic engineers, water utilities, environmental and hydrological researchers, consultants performing field flow surveys, and agencies performing flow verification in pipelines, culverts and pressurised water mains. Typical applications include flow measurement where permanent meters are absent or impractical, validation of hydraulic models, leakage studies and river/pipe studies requiring short-term in-situ measurement.

Related standards

ISO 2975 is a multi-part series. Related parts and equivalent/adopted national standards include ISO 2975-2:1975 (Constant rate injection method using non-radioactive tracers) and ISO 2975-3:1976 (Constant rate injection method using radioactive tracers — historically issued but later withdrawn). The ISO series has also been adopted/republished in national documents (for example BS 5857-1.1:1980 corresponds to ISO 2975-1:1974). For gas flow tracer methods and additional guidance see other ISO documents developed by ISO/TC 30/SC 5.

Keywords

tracer methods, flow measurement, closed conduits, dilution method, constant-rate injection, sudden injection, integration method, mean transit time, Allen velocity, mixing distance, tracer selection, non‑radioactive tracer, radioactive tracer, water flow.

FAQ

Q: What is this standard?

A: ISO 2975-1:1974 is the first (general) part of the ISO tracer-methods series for measuring water flow in closed conduits; it sets out principles, method choices and general application guidance.

Q: What does it cover?

A: It covers three principal tracer procedures (constant-rate injection, integration/sudden injection and mean transit-time), selection of tracers, determination of measuring and mixing lengths, evaluation of errors and practical field considerations for measuring water flow in closed conduits.

Q: Who typically uses it?

A: Hydraulic and environmental engineers, water utility field crews, consultants, researchers and any practitioners needing temporary or verification flow measurements in pipes, culverts or closed channels.

Q: Is it current or superseded?

A: ISO’s bibliographic record indicates ISO 2975-1:1974 remains a published International Standard and was last reviewed/confirmed by ISO’s systematic review process (confirmed in the ISO record). Users should always check the latest ISO catalogue or their national standards body for any amendments or national adoptions before relying on the standard for regulatory compliance.

Q: Is it part of a series?

A: Yes — ISO 2975 is a multi-part series addressing tracer methods. Part 2 (1975) addresses constant-rate injection using non‑radioactive tracers; Part 3 (1976) addressed radioactive tracers (historically published, later withdrawn). Other related ISO documents address tracer methods for other fluids (e.g., gases) and national equivalents exist (for example BSI publications aligning with ISO 2975 parts).

Q: What are the key keywords?

A: Tracer methods, dilution, constant-rate injection, integration/sudden injection, mean transit time, mixing distance, tracer selection, flow measurement, closed conduits.