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.
A testing dipstick is usually made of paper or cardboard and is impregnated with reagents that indicate some feature of the liquid by changing color. In medicine, dipsticks can be used to test for a variety of liquids for the presence of a given substance, known as an analyte. [1] For example, urine dipsticks are used to test urine samples for haemoglobin, nitrite (produced by bacteria in a urinary tract infection), protein, nitrocellulose, glucose and occasionally urobilinogen or ketones. [2]
They are usually brightly coloured, and extremely rough to the touch.
Dipsticks can also be used to measure the quantity of liquid in an otherwise inaccessible space, by inserting and removing the stick and then checking the extent of it covered by the liquid. The most familiar example is the oil level dipstick found on most internal combustion engines.
Other kinds of dipsticks are used to measure everything from fuel levels to the amount of beer left in an ale cask (Firkin).
"Dipstick" is the trade name of a profiling device manufactured by Face Construction Technologies of Norfolk, Virginia USA. [3] The instrument is used in 66 countries on six continents to measure the flatness and levelness of concrete floor slabs and pavements. [3] [4]
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. [5] 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. [6]
F-Number measurement procedures were established by ASTM Standard E1155. [7] 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. [3]
The U.S. Federal Highway Administration (FHWA) [8] and the World Bank (with its International Roughness Index... or "IRI") [9] have established measurement procedures using Dipstick profiler data. [10]
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." [11]
The Dipstick, with a reported accuracy of .01 mm ( 0.0004 inches), measures "true" profiles [12] and is the most widely used and accepted Class 1 profiler for the purposes of calibrating other profilers. [3] [13] 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. [14]
The instrument was similarly used to produce reference measurements [15] 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 [16] and super highways to rough unpaved roads. [15]
A viscometer is an instrument used to measure the viscosity of a fluid. For liquids with viscosities which vary with flow conditions, an instrument called a rheometer is used. Thus, a rheometer can be considered as a special type of viscometer. Viscometers only measure under one flow condition.
In measurement technology and metrology, calibration is the comparison of measurement values delivered by a device under test with those of a calibration standard of known accuracy. Such a standard could be another measurement device of known accuracy, a device generating the quantity to be measured such as a voltage, a sound tone, or a physical artifact, such as a meter ruler.
A pothole is a depression in a road surface, usually asphalt pavement, where traffic has removed broken pieces of the pavement. It is usually the result of water in the underlying soil structure and traffic passing over the affected area. Water first weakens the underlying soil; traffic then fatigues and breaks the poorly supported asphalt surface in the affected area. Continued traffic action ejects both asphalt and the underlying soil material to create a hole in the pavement.
Rumble strips are a road safety feature to alert inattentive drivers of potential danger, by causing a tactile vibration and audible rumbling transmitted through the wheels into the vehicle interior. A rumble strip is applied along the direction of travel following an edgeline or centerline, to alert drivers when they drift from their lane. Rumble strips may also be installed in a series across the direction of travel, to warn drivers of a stop or slowdown ahead, or of an approaching danger spot.
The Manual on Uniform Traffic Control Devices for Streets and Highways is a document issued by the Federal Highway Administration (FHWA) of the United States Department of Transportation (USDOT) to specify the standards by which traffic signs, road surface markings, and signals are designed, installed, and used. In the United States, all traffic control devices must legally conform to these standards. The manual is used by state and local agencies as well as private construction firms to ensure that the traffic control devices they use conform to the national standard. While some state agencies have developed their own sets of standards, including their own MUTCDs, these must substantially conform to the federal MUTCD.
The AASHO Road Test was a series of experiments carried out by the American Association of State Highway and Transportation Officials (AASHTO), to determine how traffic contributed to the deterioration of highway pavements.
The pavement condition index (PCI) is a numerical index between 0 and 100, which is used to indicate the general condition of a pavement section. The PCI is widely used in transportation civil engineering and asset management, and many municipalities use it to measure the performance of their road infrastructure and their levels of service. It is a statistical measure and requires manual survey of the pavement. This index was originally developed by the United States Army Corps of Engineers as an airfield pavement rating system, but later modified for roadway pavements and standardized by the ASTM. The surveying processes and calculation methods have been documented and standardized by ASTM for both roads and airport pavements:
Samuel Allen Face Jr. was an American inventor and co-developer of some of the most important advances in concrete floor technology and wireless controls.
Road slipperiness is a condition of low skid resistance due to insufficient road friction. It is a result of snow, ice, water, loose material and the texture of the road surface on the traction produced by the wheels of a vehicle.
Road surface textures are deviations from a planar and smooth surface, affecting the vehicle/tyre interaction. Pavement texture is divided into: microtexture with wavelengths from 0 mm to 0.5 millimetres (0.020 in), macrotexture with wavelengths from 0.5 millimetres (0.020 in) to 50 millimetres (2.0 in) and megatexture with wavelengths from 50 millimetres (2.0 in) to 500 millimetres (20 in).
The concrete slump test measures the consistency of fresh concrete before it sets. It is performed to check the workability of freshly made concrete, and therefore the ease with which concrete flows. It can also be used as an indicator of an improperly mixed batch. The test is popular due to the simplicity of apparatus used and simple procedure. The slump test is used to ensure uniformity for different loads of concrete under field conditions.
For concrete cracking see Crazing
The international roughness index (IRI) is the roughness index most commonly obtained from measured longitudinal road profiles. It is calculated using a quarter-car vehicle math model, whose response is accumulated to yield a roughness index with units of slope. Although a universal term, IRI is calculated per wheelpath, but can be expanded to a Mean Roughness Index (MRI) when both wheelpath profiles are collected. This performance measure has less stochasticity and subjectivity in comparison to other pavement performance indicators, such as PCI, but it is not completely devoid of randomness. The sources of variability in IRI data include the difference among the readings of different runs of the test vehicle and the difference between the readings of the right and left wheel paths. Despite these facts, since its introduction in 1986, the IRI has become the road roughness index most commonly used worldwide for evaluating and managing road systems.
A measuring instrument is a device to measure a physical quantity. In the physical sciences, quality assurance, and engineering, measurement is the activity of obtaining and comparing physical quantities of real-world objects and events. Established standard objects and events are used as units, and the process of measurement gives a number relating the item under study and the referenced unit of measurement. Measuring instruments, and formal test methods which define the instrument's use, are the means by which these relations of numbers are obtained. All measuring instruments are subject to varying degrees of instrument error and measurement uncertainty. These instruments may range from simple objects such as rulers and stopwatches to electron microscopes and particle accelerators. Virtual instrumentation is widely used in the development of modern measuring instruments.
Diamond grinding is a pavement preservation technique that corrects a variety of surface imperfections on both concrete and asphalt concrete pavements. Most often utilized on concrete pavement, diamond grinding is typically performed in conjunction with other concrete pavement preservation (CPP) techniques such as road slab stabilization, full- and partial-depth repair, dowel bar retrofit, cross stitching longitudinal cracks or joints and joint and crack resealing. Diamond grinding restores rideability by removing surface irregularities caused during construction or through repeated traffic loading over time. The immediate effect of diamond grinding is a significant improvement in the smoothness of a pavement. Another important effect of diamond grinding is the considerable increase in surface macrotexture and consequent improvement in skid resistance, noise reduction and safety.
The Hermes Road Measurement System is the result of the EU-funded project Innovative, Highly Efficient Road Surface Measurement and Control System that was undertaken between August 2012 and July 2014. The project was funded through the European Union's Seventh Framework Capacities Programme that aimed at supporting research for the benefit of small-to-medium enterprises (SMEs). This is realised by cooperation between a group of SMEs from several European countries, working in collaboration with a number of research and technological development (RTD) institutes, collectively constituting the project's consortium.
Pavement performance modeling or pavement deterioration modeling is the study of pavement deterioration throughout its life-cycle. The health of pavement is assessed using different performance indicators. Some of the most well-known performance indicators are Pavement Condition Index (PCI), International Roughness Index (IRI) and Present Serviceability Index (PSI), but sometimes a single distress such as rutting or the extent of crack is used. Among the most frequently used methods for pavement performance modeling are mechanistic models, mechanistic-empirical models, survival curves and Markov models. Recently, machine learning algorithms have been used for this purpose as well. Most studies on pavement performance modeling are based on IRI.
The rolling straight-edge is an instrument used to measure the surface regularity of roads and similar structures such as airport runways. It consists of a straightedge of a fixed distance mounted on wheels with a sensor at the centrepoint measuring deviation in height. It is rolled along the road surface and set to specific trigger levels which can be logged automatically or by means of an audible alarm. The rolling straight-edge was developed by the British Road Research Laboratory to replace earlier manual methods of measurement using rulers. It has been used by several countries and remains in use in the United Kingdom, Germany and Taiwan.
The present serviceability index (PSI) is a pavement performance measure. Introduced by the American Association of State Highway and Transportation Officials (AASHTO), the PSI is one of the most widely used pavement performance indicators after pavement condition index (PCI) and international roughness index (IRI). This performance indicator ranges between 0 and 5, 0 representing a failed pavement and 5 an excellent one. Since the PSI entails slope variance, it is correlated with performance indicators related to roughness such as IRI.
