A pocket comparator is an optical device for measuring and inspection comprising a loupe and a reticle.[1] The instrument was developed and manufactured by the Bell & Howell Company, but similar instruments of other names are made by other manufacturers.[2][3]
Reticle of Bell & Howell Pocket ComparatorTypographer Henri Friedlaender at work. Note Pocket Comparator at 01:10.
It is used for:
Linear measurements in fractions of an inch[4][5][6]
Circular measurements in fractions of an inch
Radius measurements
Angle measurements
Narrow line width measurements[7]
Circular measurements in decimals of an inch
Linear measurements in inches
Linear measurements in millimeters
Measurements are performed by bringing the surface of the reticle as close as possible to the work inspected.[8]
^"The Pocket Comparator - A New Optical Measuring Instrument". in: Electrical Engineering (Volume 69, Issue 3, p. 220) March 1950 http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=6433729&url=http%3A%2F%2Fieeexplore.ieee.org%2Fstamp%2Fstamp.jsp%3Ftp%3D%26arnumber%3D6433729
^" by Marcus Bowman Crowood, 31 August 2015, Crafts & Hobbies
^"Low price measuring magnifier uses real glass reticle", Journal of the Franklin Institute, 1955, Vol. 259(6), pp. 516–516 [peer reviewed journal]
^Charles C. Ryerson and Anthony J. Gow: Ship Superstructure Icing:
Crystalline and Physical Properties in: US Army Corps of Engineers® Engineer Research and Development Center (August 2000) p. 14
^van Altena, W. F., Low-luminosity members of the Hyades cluster. Astronomical Journal, Vol. 71, p. 482–512 (1966)
^I. B. A. Menown, G. MacKenzie and A. A. J. Adgey, Optimizing the initial 12-lead electrocardiographic diagnosis of acute myocardial infarction, European Heart Journal (2000) 21, 275–283
^DEPARTMENT OF THE ARMY EM 1110-2-2002 U.S. Army Corps of Engineers: EVALUATION AND REPAIR OF CONCRETE STRUCTURES p.2-11 http://www.publications.usace.army.mil/Portals/76/Publications/EngineerManuals/EM_1110-2-2002.pdf
^The Pocket Comparator: A New Measuring Instrument, in: INDUSTRIAL QUALITY CONTROL VOL.6 NO.5, March 1950 pp. 22-23
A pocketcomparator is an optical device for measuring and inspection comprising a loupe and a reticle. The instrument was developed and manufactured...
documents requiring cleaning or repair. Bioptic telescope Loupe light Pocketcomparator Webster's New World College Dictionary (4th ed.). Houghton Mifflin...
parts and construction Monocle Optical microscope Optical telescope Pocketcomparator Clark, Roger N. (1990). Visual Astronomy of the Deep Sky. Cambridge...
measuring devices List of physical quantities List of sensors Metrology Pocketcomparator Sensor or detector Timeline of temperature and pressure measurement...
ceftaroline-treated subjects was 2.7% compared to a rate of 3.7% for the comparator group-treated subjects. The most common adverse reactions occurring in...
include fuzzy aspects in the SQL statements, like fuzzy conditions, fuzzy comparators, fuzzy constants, fuzzy constraints, fuzzy thresholds, linguistic labels...
the list and prices of new drugs, as the listed drugs could become the comparators for new drugs in the economic evaluation. Furthermore, in South Korea...
their mass measured directly. This is because balances ("dual-pan" mass comparators) compare the gravitational force exerted on the person on the platform...
framework provides the NSArray -indexOfObject:inSortedRange:options:usingComparator: method in Mac OS X 10.6+. Apple's Core Foundation C framework also contains...
for IBM System/3's 96 column cards IBM 9900: Continuous Multiple Access Comparator IBM 072: Alphabetic Collator IBM 077: Electric Punched Card Collator;...
video amplifier Analog electronics – analog circuit, analog amplifier, comparator, integrator, summer, multiplier, analog filter, inverter Biomedical engineering...
amplifiers, video amplifiers/buffers/filters, variable gain amplifiers, comparators, voltage, other specialty amplifiers and products for special linear...
of 94% of 51 EVALI patients and in none in 99 healthy controls in the comparator group. The CDC reported that their findings suggest vaping products containing...
of the comparator group), and 100% to vest at some predetermined stretch target (e.g. if TSR is at least at the 75th percentile of the comparator group)...
Findings", October 19, 1995 1997: "Series of Investigative Reports on Comparator Systems Corp." by Cathy Taylor, Liz Pulliam and Elliot Blair Smith, Orange...