Comparative Tracking Index

Comparative Tracking Index

The Comparative Tracking Index or CTI is used to measure the electrical breakdown (tracking) properties of an insulating material. To measure the tracking, 52 drops of 0.1% ammonium chloride solution are dropped on the material, and the voltage measured for a 3mm thickness is considered representative of the material performance. Also term PTI (Proof Tracking Index) is used: it means voltage at which during testing on five samples the samples pass the test with no failures.

Tracking is an electrical breakdown on the surface of an insulating material. A large voltage difference gradually creates a conductive leakage path across the surface of the material by forming a carbonized track. Testing method is specified in IEC standard 60112.

Performance Level Categories (PLC) were introduced to avoid excessive implied precision and bias.

The CTI value is used for electrical safety assessment of electrical apparatus, as for instance carried out by Underwriters Laboratory. The minimum required creepage distances over an insulating material between electrically conducting parts in apparatus, especially between parts with a high voltage and parts that can be touched by human users, is dependent on the insulators CTI value. Also for internal distances in an apparatus by maintaining CTI based distances, the risk of fire is reduced.

Tracking Index (V) PLC
600 and Greater 0
400 through 599 1
250 through 399 2
175 through 249 3
100 through 174 4
< 100 5

In design of medical products, the CTI is treated differently. Material groups are classified as shown below, per 60601-1:2005:

Comparative Tracking Index (CTI) Material Group
600 <= CTI I
400 <= CTI < 600 II
175 <= CTI < 400 IIIa
100 <= CTI < 175 IIIb

Link

  • Underwriters Laboratory defintion of CTI [1]
  • [IEC-60601-1:2005] See Table 9 [2]

Wikimedia Foundation. 2010.

Игры ⚽ Поможем сделать НИР

Look at other dictionaries:

  • CTI — • comparative tracking index …   Maritime acronyms and abbreviations

  • Kriechstrecke — Die Kriechstromfestigkeit kennzeichnet die Isolationsfestigkeit der Oberfläche (Kriechstrecke) von Isolierstoffen, insbesondere unter Einwirkung von Feuchtigkeit und Verunreinigungen. Sie definiert den maximalen Kriechstrom, der sich unter… …   Deutsch Wikipedia

  • Kriechstromfestigkeit — Die Kriechstromfestigkeit kennzeichnet die Isolationsfestigkeit der Oberfläche (Kriechstrecke) von Isolierstoffen, insbesondere unter Einwirkung von Feuchtigkeit und Verunreinigungen. Sie definiert den maximalen Kriechstrom, der sich unter… …   Deutsch Wikipedia

  • показатель — 3.7 показатель (indicator): Мера измерения, дающая качественную или количественную оценку определенных атрибутов, выведенную на основе аналитической модели, разработанной для определенных информационных потребностей. Источник …   Словарь-справочник терминов нормативно-технической документации

  • ГОСТ Р 51731-2010: Контакторы электромеханические бытового и аналогичного назначения — Терминология ГОСТ Р 51731 2010: Контакторы электромеханические бытового и аналогичного назначения оригинал документа: 3.2.5 автоматический выключатель (circuit breaker): Контактный коммутационный аппарат, способный включать, проводить и отключать …   Словарь-справочник терминов нормативно-технической документации

  • CTI — may stand for:*The School of Computer Science, Telecommunications and Information Systems (CTI) at DePaul University *Corrugated Technologies, Inc. (CTI) *Central Tyre Inflation *Construction Testing and Inspections CTI Consultants, Inc.(CTI)… …   Wikipedia

  • Electrical breakdown — in an electric discharge showing the ribbon like plasma filaments from a Tesla coil. The term electrical breakdown or electric breakdown has several similar but distinctly different meanings. For example, the term can apply to the failure of an… …   Wikipedia

  • CTI — steht für Carinthian Tech Institute, die bis Juni 2007 gültige englische Bezeichnung der Fachhochschule Kärnten Comparative Tracking Index, ein Maß für die Kriechstromfestigkeit von Materialien Computer Telephony Integration, die Verknüpfung von… …   Deutsch Wikipedia

  • Claquage (électronique) — En électronique ou électrotechnique, le claquage est un phénomène qui se produit dans un isolant quand le champ électrique est plus important que ce que peut supporter cet isolant. Il se forme alors un arc électrique. Dans un condensateur,… …   Wikipédia en Français

  • CTI — Computer Telephony Integration (Computing » Networking) * Computer Telephone Integration (Computing » Telecom) * Comparative Tracking Index (Miscellaneous » Plastics) * Charge Transfer Inefficiency (Academic & Science » Chemistry) * Computer… …   Abbreviations dictionary

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”