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A dipstick is one of several measurement devices.
Some dipsticks are dipped into a liquid to perform a chemical test or to provide a measure of quantity of the liquid.
Since the late 20th century, a flatness/levelness measuring device trademarked "Dipstick" has been used to produce concrete and pavement surface profiles and to help establish profile measurement standards in the concrete floor and paving industries.
They are usually brightly coloured, and extremely rough to the touch.
Other kinds of dipsticks are used to measure everything from fuel levels to the amount of beer left in an cask ale cask (Firkin).
The Dipstick measures concrete floor slab flatness/levelness in terms of Face Floor Profile Numbers ("F-Numbers"), a profile measurement system adopted in 1990 by the American Concrete Institute. The Dipstick is 'walked' across sections of the floor between two successive points and data is collated. This is now regarded by some in the industry as a long slow process with other profiling devices available offering accurate results in less time. The Dipstick can have a variable sampling rate from 75mm up to 300mm.
F-Number measurement procedures were established by ASTM Standard E1155. ASTM E1155 - 96(2008) Standard Test Method for Determining FF Floor Flatness and FL Floor Levelness Numbers The instrument also measures TR-34 Free Movement (FM); TR-34 Defined Movement (DM); Gap under Sliding Unleveled Straightedge; Gap under Rolling Straightedge; and DIN 18202.
The U.S. Federal Highway Administration (FHWA) FHWA Manual for Profile Measurements and Processing, March 2009 and the World Bank (with its International Roughness Index... or "IRI") PavementInteractive.org: "Roughness" have established measurement procedures using Dipstick profiler data. Face® Dipstick® website road profiler page
The American Association of State Highway and Transportation Officials (AASHTO) has established its Standard R 41 (most recently published as R 41-05 (2010)) to, "... manually collect precision profile data utilizing the Face Technologies Dipstick. The instrument measures profiles (relative elevation differences) at a rate and accuracy greater than traditional rod and level surveys. Procedures for measuring both longitudinal and transverse profiles are described." AASHTO R 41-05 - 2010 Standard Practice for Measuring Pavement Profile Using a Dipstick
The Dipstick, with a reported accuracy of .01 mm ( 0.0004 inches), measures "true" profiles Measurements, specifications, and achievement of smoothness for pavement construction; James H. Woodstrom, National Research Council (U.S.), Transportation Research Board, Page 10 and is the most widely used and accepted Class 1 profiler for the purposes of calibrating other profilers. Comparison of Roughness Calibration Equipment - with a View to Increased Confidence in Network Level Data; G. Morrow, A. Francis, S.B. Costello, R.C.M. Dunn, 2006 Although, most state DOTs now use rolling inclinometer based systems for AASHTO r56 certification procedures which collect at the same 25mm sampling interval as highway profilers.
Dipstick was used to obtain data that were used as ground truth in FHWA evaluations of the repeatability of IRI values as measured by other profilers and in Long-Term Pavement Performance (LTTP) studies conducted by several states. FHWA Profiler Comparison Studies
The instrument was similarly used to produce reference measurements by the World Road Association (PIARC) in its 1998 "International Experiment to Harmonise Longitudinal and Transverse Profile Measurement and Reporting Procedures." The PIARC experiment was conducted in the US, Japan, Holland and Germany and included IRI values from airport runways and super highways to rough unpaved roads.
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