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A pistonphone is an acoustical calibrator (sound source) that uses a closed coupling volume to generate a precise sound pressure for the calibration of measurement microphones. The principle relies on a piston mechanically driven to move at a specified cyclic rate, pushing on a fixed volume of air to which the microphone under test is coupled.
The technicians who work in the PMEL will often specialize in one of these sections. The K-Sections are derived from the primary function of the TMDE. This is based upon the calibration authority. Most labs have three calibration sections divided into K1/K8, K5/K6 and K3/K4 that specialize in like test equipment.
Tube micrometers have a cylindrical anvil positioned perpendicularly to a spindle and is used to measure the thickness of tubes. Micrometer stops are micrometer heads that are mounted on the table of a manual milling machine, bedways of a lathe, or other machine tool, in place of simple stops. They help the operator to position the table or ...
A set of gauge blocks are used as a working standard to check the calibration of measurement tools such as micrometers.. An example of a primary standard was the international prototype of the kilogram (IPK) which was the master kilogram and the primary mass standard for the International System of Units (SI).
A gauge block is a block of metal or ceramic with two opposing faces ground precisely flat and parallel, a precise distance apart. Standard grade blocks are made of a hardened steel alloy, while calibration grade blocks are often made of tungsten carbide (WC), chromium carbide (CrC) or ceramic (SiO 2-based) because they are harder and wear less ...
Volumetric pipettes or bulb pipette allow the user to measure a volume of solution extremely precisely (precision of four significant figures). These pipettes have a large bulb with a long narrow portion above with a single graduation mark as it is calibrated for a single volume (like a volumetric flask). Typical volumes are 20, 50, and 100 mL.
The formal definition of calibration by the International Bureau of Weights and Measures (BIPM) is the following: "Operation that, under specified conditions, in a first step, establishes a relation between the quantity values with measurement uncertainties provided by measurement standards and corresponding indications with associated measurement uncertainties (of the calibrated instrument or ...
Glass chart. A 1951 USAF resolution test chart is a microscopic optical resolution test device originally defined by the U.S. Air Force MIL-STD-150A standard of 1951. The design provides numerous small target shapes exhibiting a stepped assortment of precise spatial frequency specimens.