counter


counter
A device that counts, usually scintillations.
- automated differential leukocyte c. an instrument using digital imaging or cytochemical techniques to differentiate leukocytes.
- electronic cell c. an automatic blood cell c. in which cells passing through an aperture alter resistance and are counted as voltage pulses, or in which cells passing through a flow cell deflect light; some types of c. are capable of multiple simultaneous measurements on each blood sample; e.g., leukocyte count, red cell count, hemoglobin, hematocrit, and red cell indices.
- Geiger-Müller c. an instrument for measuring radioactivity by counting the emission of radioactive particles; it consists of a metallic cylinder, negatively charged, in a tube containing a fine, positively charged wire at its center; radiations produce ionization of the gas molecules between the cylinder and the wire and result in an electrical discharge independent of the energy of the impinging particle or ray.
- proportional c. a Geiger-Müller c. operating in the voltage range and under conditions in which pulse height is proportional to the energy of the particles or rays being counted, thus making discrimination between particles or rays of different energies possible.
- scintillation c. an instrument used for the detection of radioactivity; the radiation is absorbed by a scintillator (a crystal or a compound, such as POPOP, in solution) which results in minute flashes of light that are detected by a photocathode. The resultant electron emission is amplified by a photomultiplier and an amplifier. SYN: scintillometer, spinthariscope.
- well c. a scintillation crystal shaped with a central hole to receive a small sample, plus associated detector and electronics.
- whole-body c. shielding and instrumentation, usually involving more than one detector, designed to evaluate the total-body burden of various gamma-emitting nuclides.

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count·er 'kau̇nt-ər n a level surface over which transactions are conducted or food is served or on which goods are displayed or work is conducted <a lunch \counter> - over the counter without a prescription <drugs available over the counter>
counter n one that counts esp a device for indicating a number or amount see GEIGER COUNTER

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coun·ter (kounґtər) an instrument or apparatus by which numerical value is computed; in radiology, a device for enumerating ionizing events.

Medical dictionary. 2011.

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  • Counter — Coun ter, a. Contrary; opposite; contrasted; opposed; adverse; antagonistic; as, a counter current; a counter revolution; a counter poison; a counter agent; counter fugue. Innumerable facts attesting the counter principle. I. Taylor. [1913… …   The Collaborative International Dictionary of English

  • counter — coun‧ter [ˈkaʊntə ǁ ər] noun [countable] 1. COMMERCE the place where you are served in a shop, bank etc: • Please pay at the checkout counter. ˈtrade ˌcounter COMMERCE a part of a shop, factory, or website where a business can buy goods for less… …   Financial and business terms

  • counter — Ⅰ. counter [1] ► NOUN 1) a long flat topped fitment over which goods are sold or served or across which business is conducted with customers. 2) a small disc used in board games for keeping the score or as a place marker. 3) a token representing… …   English terms dictionary

  • counter — counter1 [kount′ər] n. [ME countour: in senses 1 & 2 < OFr conteor < L computator < computare; in senses 3, 4, 5 < OFr contouer, counting room, table of a bank < ML computatorium < L computare,COMPUTE] 1. a) a person or thing… …   English World dictionary

  • Counter — Coun ter, adv. [F. contre, fr. L. contra against. Cf. {Contra }.] 1. Contrary; in opposition; in an opposite direction; contrariwise; used chiefly with run or go. [1913 Webster] Running counter to all the rules of virtue. Locks. [1913 Webster] 2 …   The Collaborative International Dictionary of English

  • counter- — coun·ter / kau̇n tər/ prefix 1 a: contrary: opposite counter letter b: opposing: retaliatory counter action 2: complementary: corresponding …   Law dictionary

  • Counter- — Coun ter (koun t[ e]r ). Note: [See {Counter}, adv. ] A prefix meaning contrary, opposite, in opposition; as, counteract, counterbalance, countercheck. See {Counter}, adv. & a. [1913 Webster] …   The Collaborative International Dictionary of English

  • Counter — Count er (koun t[ e]r), n. [OE. countere, countour, a counter (in sense 1), OF. contere, conteor, fr. conter to count. See {Count}, v. t. ] 1. One who counts, or reckons up; a calculator; a reckoner. [1913 Webster] 2. A piece of metal, ivory,… …   The Collaborative International Dictionary of English

  • Counter — Coun ter, n. [See {Counter}, adv., {Contra}.] 1. (Naut.) The after part of a vessel s body, from the water line to the stern, below and somewhat forward of the stern proper. [1913 Webster] 2. (Mus.) Same as {Contra}. Formerly used to designate… …   The Collaborative International Dictionary of English

  • counter — [adj] opposite, opposing adverse, against, antagonistic, anti, antipodal, antipodean, antithetical, conflicting, contradictory, contrary, contrasting, converse, diametric, hindering, impeding, obstructive, obverse, opposed, polar, reverse;… …   New thesaurus

  • Counter — Coun ter, n. [OE. countour, OF. contouer, comptouer, F. comptoir, LL. computatorium, prop., a computing place, place of accounts, fr. L. computare. See {Count}, v. t.] A table or board on which money is counted and over which business is… …   The Collaborative International Dictionary of English