What is the medical definition of a penetrameter?
Medical Definition of penetrameter. : an instrument for measuring the penetrating power of radiation (as X-rays) by comparing transmission through different absorbers. — called also penetrometer.
What is the purpose of a penetrometer?
11.1 Definition, Types of Penetrometers, and Uses A penetrometer is any device forced into the soil to measure resistance to vertical penetration (Davidson, 1965). The earliest soil penetrometers were fists, thumbs, fingernails, pointed sticks, and metal rods. They are still used for qualitative measurements.
What is a standard penetrameter used for in radiography?
In taking a radiograph, it is imperative that a standard penetrameter (also called an image quality indicator) is placed on the part being radiographed.
What are the different types of penetrometer?
There are many types of penetrometer designed to be used on soil. They are usually round or cone shaped. The penetrometer is dropped on the test subject or pressed against it and the depth of the resulting hole is measured. The measurements find whether the soil is strong enough to build a road on.
What is the purpose of a Penetrameter?
It is tool to measure the contrast or change in density on an image for a known change in thickness in the specimen. Penetrameter provides an effective check on the overall quality of the radiographic inspection.
What is a penetrometer in radiography?
Penetrometers are used to determine the optimal exposure settings for performing an X-ray of a particular part of the body. They typically consist of a series of metal (usually aluminum) plates of increasing thickness. Sometimes they are arranged in the form of stair steps.
How many types of IQI are there?
There are four broad patterns of IQI in use today - the wire type, the step/hole type, the hole-in-plaque type and the duplex wire type. The first three of these are widely specified in many Standards for film radiography.
What is IQI and its types?
IQI is a set of standard wires having standard diameter. (Hole type IQI is also used. In that case it will be standard thickness plates with standard diameter holes). The IQI is placed on a radiography film while doing the radiography. The image will be caught in the film.
When referring to a 2T or 4T hole in the ASTM Penetrameter T refers to?
When referring to a "2T" or "4T" hole in the ASTM penetrameter, the T refers to: the penetrameter thickness. A graph which expresses the relationship between the logarithm of the exposure applied to a photographic material and the resulting photographic density is called: the characteristic curve.
What is 2 2T sensitivity?
Therefore, a 2-2T call-out would mean that the shim thickness should be two percent of the material thickness and that a hole that is twice the IQI thickness must be detectable on the radiograph.
What is the main purpose of an IQI when used in radiography?
IQI – Image Quality Indicator – is a device for showing the quality of a radiograph. The quality of a radiograph determines the amount of detail that can be shown.
What type of IQI is most suitable for weld inspection?
Hole type IQIs can be placed adjacent to or on the weld. Wire IQIs are placed on the weld so that the length of the wires is perpendicular to the length of the weld.
What causes geometric unsharpness?
Geometric unsharpness is caused by aspects of the geometry of the X-ray beam. Two principal factors play simultaneously: the apparent focal spot size and the ratio between object-film distance (OFD) and focus-film distance (FFD).
How many wires are in each set of a wire type IQI?
Each indicator consists of a series of seven parallel wires of different thickness mounted and encapsulated between two thin sheets of transparent, flexible PVC.
How is IQI sensitivity calculated?
As with the wire IQI, the material and dimensions of the step wedge are selected to match the application. The diameter of the smallest hole visible on the radiograph determines the sensitivity, this being calculated as hole diameter divided by component thickness expressed as a percentage.
Which isotope is used in radiography?
Two of the more common industrial gamma-ray sources for industrial radiography are iridium-192 and cobalt-60. These isotopes emit radiation in a few discreet wavelengths. Cobalt-60 will emit a 1.33 and a 1.17 MeV gamma ray, and iridium-192 will emit 0.31, 0.47, and 0.60 MeV gamma rays.
What is film contrast in radiography?
Film contrast refers to density differences that result due to the type of film used, how it was exposed, and how it was processed. Since there are other detectors besides film, this could be called detector contrast, but the focus here will be on film.
What is sensitivity in radiography?
In industrial radiography, Radiographic Sensitivity is a QUALITATIVE term referring to the size of the smallest detail that can be recorded and discernible on the film/radiograph, or to the ease with which the images of small details can be recorded.
What is the purpose of a penetrometer?
Penetrometers have been employed to measure lava's rheological properties from the first published measurement by Einarsson (1949) until recently (Belousov and Belousova, 2018).
How does a penetrometer work?
A cleaned and dried sample is placed in the penetrometer, which holds a known amount of mercury at the start of the test. It is sealed and placed in a low pressure port, where the sample is evacuated to remove air and moisture—the user controls the speed of the evacuation and there's no need for a separate preparation unit. The penetrometer cup and capillary stem are then automatically backfilled with mercury. Excess mercury is automatically drained back into the internal reservoir; only a small amount remains in the penetrometer. As pressure on the filled penetrometer increases, mercury intrudes into the sample's pores, beginning with those pores of largest diameter. This requires that mercury moves from the stem into the cup, resulting in a decreased capacitance between the now shorter mercury column inside the stem and the metal cladding on the outer surface of the stem. The instrument automatically collects low pressure measurements over the range of pressures specified by the operator. Then, the penetrometer is moved to the high pressure chamber, where high pressure measurements (> 2000 psi) are taken (up to 60,000 psi). Data are automatically reduced using the low and high pressure data points, along with values entered by the operator, such as the weight of the sample and the weight of the penetrometer loaded with mercury.
How are penetrometers used to determine soil properties?
Penetrometers have been used as a minimally invasive, rapid, and consequently inexpensive method of determining soil properties, in situ (e.g. Mitchell and Brandon, 1998 ). Originally developed to correlate measurements of penetration resistance with magnitudes of soil strength, techniques have been extended to incorporate both measurement and analysis of penetration-generated pore fluid pressures. The generation and subsequent dissipation of these fluid pressures are related to the transport properties of the penetrated medium, and this response may be used to determine permeability, directly. Specifically, the peak magnitude of pore fluid pressure, measured at the tip, and its rate of dissipation, may be correlated directly with permeability magnitudes. Pore fluid pressures are generated by the mechanical displacement of the soil surrounding the penetrometer tip, represented in its simplest form as hydromechanical coupling ( Elsworth, 1993; Elsworth, 1998). Measured pore pressure magnitudes may be correlated with empirical (Robertson et al., 1986) and process-based ( Levadoux and Baligh, 1986) models for behavior, either incorporating models of failure in the tip-process zone ( Teh and Houlsby, 1991, Song et al., 1999 ), or accommodating pseudo-linearized behavior ( Elsworth, 1993 ). The pore pressure response may be used to determine permeability magnitudes around the tips of terrestrial cone penetrometers, advanced either from the surface ( Elsworth and Lee, 2003) or beyond the base of evolving drill-holes (Long et al., 2003), or from marine lances, freefalling through the water column and self-embedding into soft sediments on the seafloor ( Lee and Elsworth, 2003 ). Similar approaches can be applied to each, the specifics of which are documented in the following.
What are penetrometers used for?
However, penetrometers are designed to give quantitative measurements of soil penetration resistance for a more precise correlation with properties such as bearing value, safe soil pressure, rolling resistance, trafficability of wheels or crawler tracks on soil, relative density, crop yield, and tilth (Davidson, 1965 ).
How to measure soil strength?
Perhaps the most widely used device to measure soil strength in the field is the cone penetrometer. Although the cone penetrometer was developed to determine the mobility of off-road vehicles at the Waterways Experiment Station in Vicksburg, Mississippi, USA, it has been used to predict traction, draft requirements of tillage implements, and to quantify soil strength to indicate soil-compaction level and impedance to root growth. The most common form of this device consists of a polished steel cone, which is pushed against the soil and then the force of penetration is measured. The American Society of Agricultural Engineers (ASAE) has developed a standard (S313.3) that describes the geometry of a standard cone penetrometer, whereas a second standard (EP542) outlines the proper procedure for using this device.
When a penetrometer penetrates into a new layer, the toe capacity is not fully mobilized?
Several studies such as De Beer (1963), Meyerhof (1983), and Gui and Bolton (1998) indicate that when penetrometer or a pile penetrates into a new layer, the toe capacity is not fully mobilized. The full mobilization occurs when the pile or penetrometer advances sufficiently in the target layer. The embedment depth is a function of pile diameter and is expressed as a multiple of pile diameter.
What does the hyperbolic arrivals on a radargram indicate?
Hyperbolic arrivals ( arrows) indicate the presence of diffractors buried beneath the surface, possibly associated with human burials. Reflections from soil layering are also present ( dashed lines)
penetrometer
an instrument for measuring the penetrating power of x-rays; qualimeter.
penetrometer
An obsolete device formerly used to quantify an X-ray’s penetrability, or “hardness”.
step wedge
Triangular aluminum device placed over a radiographic film during exposure to determine the penetrating ability of an x-ray beam.
What is a penetrometer?
Penetrometers are devices to measure the force needed to push a metal rod of known diameter into a growing medium. They may be hand operated and portable or machine driven and stationary.
What is constant speed penetrometry?
Here, a penetrating body is mechanically driven into a fat specimen at a constant speed while the force is continuously recorded. Constant speed penetrometry permits control over penetration depth and allows hardness values as a function of penetration depth to be evaluated from the load–displacement curve as the fat specimen is indented ( Boodhoo et al., 2009 ). An additional advantage of constant speed penetrometers, where the load–displacement response is monitored on unloading, is that the elasticity of the sample can be derived from the penetrometer test ( Page, 1996 ). Load–unloading cycles of a cone penetrating a simulated vegetable shortening to two different depths are shown in Fig. 5.17.
How to measure soil strength?
Perhaps the most widely used device to measure soil strength in the field is the cone penetrometer. Although the cone penetrometer was developed to determine the mobility of off-road vehicles at the Waterways Experiment Station in Vicksburg, Mississippi, USA, it has been used to predict traction, draft requirements of tillage implements, and to quantify soil strength to indicate soil-compaction level and impedance to root growth. The most common form of this device consists of a polished steel cone, which is pushed against the soil and then the force of penetration is measured. The American Society of Agricultural Engineers (ASAE) has developed a standard (S313.3) that describes the geometry of a standard cone penetrometer, whereas a second standard (EP542) outlines the proper procedure for using this device.
What is the most commonly used shear instrument for meat tenderness?
The most commonly used device for the evaluation of meat tenderness is the Warner–Bratzler shear, shown in Fig. 3.6. The force necessary to shear a cylindrical sample of meat 1.27 or 2.54 cm in diameter against the dull edge of a triangular opening is measured ( Bratzler, 1932 ). The shearing portion of this instrument may be adapted for attachment to a UTM. If used in this manner, two parameters may be measured as described by Larmond and Petrasovits (1972). Firmness in kilograms per minute is calculated as the slope of the line drawn from the origin of the curve to the peak and shear cohesiveness is defined as the peak force in kilograms. Sensory scores usually are highly correlated with Warner–Bratzler shear values, possibly because the dull edge against which the meat is torn simulates the grinding surfaces of the teeth, which also are dull. However, some investigators have shown weak correlation between Warner–Bratzler shear values and sensory scores for tenderness. Care must be exercised when cylindrical samples or cores are removed from the meat. Meat should be at room or refrigerator temperature to avoid irregularly shaped cores. Williams et al., (1983) indicated that shear value varies with position in the muscle, thus reinforcing the need to be consistent in position of taking cores for Warner–Bratzler shear testing. Differences were found between longissimus samples stored for 2 hr before coring and for longer times. Thus time of holding before coring is also a source of variation in values. Kastner and Henrickson (1969) suggested that a mechanical device be used to ensure cores of uniform diameter. Cores usually are taken so that shearing occurs at a 90° angle to the fiber. Applying force at that angle takes more force than applying force parallel to the fibers ( Murray and Martin, 1980 ). Szczesniak (1986) reviewed factors that affect shear values.
Soil
There are many types of penetrometer designed to be used on soil. They are usually round or cone shaped. The penetrometer is dropped on the test subject or pressed against it and the depth of the resulting hole is measured. The measurements find whether the soil is strong enough to build a road on.
Botany
A penetrometer may be used in botany to find the toughness of a leaf by measuring the force needed to punch a hole of a certain size through the leaf.
Science
Penetrometers equipped with a known needle and mass are used to determine the hardness of bitumen and thus its efficacy and material properties when applied to roads as asphalt concrete .
Food Products
Penetrometers are used for objective evaluation of food products. Penetrometers, equipped with a plunger and a needle or cone, penetrate food samples through gravitational force for a selected period of time.
External links
University of Arizona document, "An impact penetrometer for a landing spacecraft."
Types of image quality indicator
The image quality indicator is categorized by either a hole-type IQI containing three different sized holes or a wire-type IQI containing six different sized wires.
Radiograph film acceptance criteria
A radiograph is considered acceptable if the entire outline of the IQI is visible, the hole or wires are discernable, and the density of the film is within the required range.
Placement of image quality indicator
For achieving the best result, the image quality indicator should be placed on the source side of the part being examined at the nearest possible point from the radiation source.
WHAT ARE IMAGE QUALITY INDICATORS (IQIs), THEIR SELECTION & PLACEMENT?
For establishing the quality of an image, an Image Quality Indicator, or penetrameter, is used during Radiographic Testing. The idea is to place a Penetrameters or IQI on a specimen that is being radiographically tested, to evaluate the sensitivity of the radiograph.
Radiographic Sensitivity
Radiographic sensitivity is defined as the smallest or thinnest material change that a radiograph or RT film after exposure can reveals.
Hole Type IQI
In the early times of radiographic inspection, you would put, in front of the piece to be inspected, a plate with a perforation the size of the smallest discontinuity you wanted to find in that piece. That was known as a “Hole Type” IQI. However, nowadays the most used type of IQI is the “Wire-type IQI”.
Wire Type IQI
Wire-type IQIs come in four sets (Set A, Set B, Set C, Set D) containing six wires each of different diameters. Sets A, B C, D are selected depending on the thickness of the piece to be evaluated.
How to make the selection of Image Quality Indicators ( IQI)?
Let´s say you need to select a penny for a piece 6,4mm thick with an 1/8″ reinforcement in each side (The picture of the radiographic film in this article corresponds to that situation). Then the single wall thickness would be 2/4″ = 12,7mm. If you need 2% sensitivity, then multiply 12,7*0,02 = 0,254mm.