Commonly used in the textile industry, which unit of thermal resistance is used to measure the thickness of duvets?
"G in W/mK then a handy backronym for remembering what Tog means is ""10/G"", or ""Ten Over G."" Tog (unit) The tog is a measure of thermal insulance of a unit area, also known as thermal resistance. It is commonly used in the textile industry and often seen quoted on, for example, duvets and carpet underlay. The Shirley Institute in Manchester, England developed the tog as an easy-to-follow alternative to the SI unit of mK/W. The name comes from the informal word ""togs"" for 'clothing', which itself was probably derived from the word ""toga"", a Roman garment. The basic unit"
"apparatus for duvet tog testing. This consists of a metal plate at least 1000 mm x 600 mm at skin temperature (33°C) arranged to support the whole duvet, and a mechanism for measuring the air temperature above the quilt. This requires very precise control of the laboratory environment in order to get reliable results. BS 8510 describes tog testing for baby products, the concern here being to ensure that babies do not overheat. Measurement of the clo, a similar measure used in the USA, is described in ASTM D-1518. If we call the reciprocal of the insulation coefficient, the conductance"
"for comfortable warmth while the moisture produced, most likely sweat, is supposed to evaporate. It retains its insulating properties when wet. The thermal resistance R-value provided by Thinsulate products varies by the specific thickness and construction of the fabric. Values (US units) range from 1.6 for 80-gram fabric to 2.9 for 200-gram fabric. Thinsulate is considered ""the warmest thin apparel insulation"" available. In fact, when equal thicknesses are compared, it provides about 1½ times the warmth of down and about twice the warmth of other high-loft insulation materials. Material safety data sheets from the manufacturer show that different varieties of"
"the performance of their duvets in togs, a measurement of thermal insulation. This enables the purchaser to select a duvet appropriate to the season: the higher the tog rating, the warmer the duvet. A few manufacturers have marketed combined duvet set consisting of one 4.5 tog and one 9.0 tog. The light-weight one is for summer and the medium one for spring and autumn; snapped together, 13.5 togs is designed for winter. Manufacturers may also offer up to 15 tog duvets. Modern manufacturing conventions have resulted in a large number of sizes and standards. The term ""duvet day"" is used"
"Thermal resistance Thermal resistance is a heat property and a measurement of a temperature difference by which an object or material resists a heat flow. Thermal resistance is the reciprocal of thermal conductance. Absolute thermal resistance is the temperature difference across a structure when a unit of heat energy flows through it in unit time. It is the reciprocal of thermal conductance. The SI units of thermal resistance are kelvins per watt or the equivalent degrees Celsius per watt (the two are the same since the intervals are equal: Δ1 K = Δ1 °C). The thermal resistance of materials is"
"Resistance thermometer Resistance thermometers, also called resistance temperature detectors (RTDs), are sensors used to measure temperature. Many RTD elements consist of a length of fine wire wrapped around a ceramic or glass core but other constructions are also used. The RTD wire is a pure material, typically platinum, nickel, or copper. The material has an accurate resistance/temperature relationship which is used to provide an indication of temperature. As RTD elements are fragile, they are often housed in protective probes. RTDs, which have higher accuracy and repeatability, are slowly replacing thermocouples in industrial applications below 600 °C. Common RTD sensing elements"
"Tear resistance Tear resistance (or tear strength) is a measure of how well a material can withstand the effects of tearing. It is a useful engineering measurement for a wide variety of materials by many different test methods. For example with rubber, tear resistance measures how the test specimen resists the growth of any cuts when under tension, it is usually measured in kN/m. Tear resistance can be measured by the ""ASTM D 412"" method (the same used to measure tensile strength, modulus and elongation). ASTM D 624 can be used to measure the resistance to the formation of a"
"the walls are sufficiently insulated. Like resistance in electrical circuits, increasing the physical length (for insulation, thickness) of a resistive element, such as graphite for example, increases the resistance linearly; double the thickness of a layer means double the R-value and half the heat transfer; quadruple, quarters; etc. In practice, this linear relationship does not hold for compressible materials such as glass, wool, and cotton batting whose thermal properties change when compressed. To find the average heat loss per unit area, simply divide the temperature difference by the R-value for the layer. If the interior of a home is at"
"and that the sleeper is unclothed. Sleepwear and such other layers can make a significant difference for the lower tog values. A few manufacturers have marketed combined duvet sets consisting of two duvets; one of approximately 4.5 tog and one of approximately 9.0 tog. These can be used individually as summer (4.5 tog) and spring/autumn (9.0 tog). When joined together using press studs around the edges, or Velcro strips across each of the corners, they become a 13.5 tog winter duvet and as such can be made to suit all seasons. The tog is also used to define the thermal"
"reciprocal of thermal conductivity is called thermal resistivity. The general equation for thermal conductivity is formula_1, where formula_2 is the heat flux, formula_3 is the thermal conductivity and formula_4 is the temperature gradient. In the International System of Units (SI), thermal conductivity is measured in watts per meter-kelvin (W/(m⋅K)). Some papers report in watts per centimeter-kelvin (W/(cm⋅K)). In imperial units, thermal conductivity is measured in BTU/(hr⋅ft⋅°F). The dimension of thermal conductivity is MLTΘ, expressed in terms of the dimensions mass (M), length (L), time (T), and temperature (Θ). Other units which are closely related to the thermal conductivity are in"
"of W/(mK) and U.S. units of BTU/(hr °F ft); where formula_5 is the heat flux, formula_6 is the temperature difference across the material, ""k"" is the material's coefficient of thermal conductivity and ""L"" is its thickness. In some contexts, ""U"" is referred to as unit surface conductance. See also: tog (unit) or Thermal Overall Grade (where 1 tog = 0.1 m·K/W), used for duvet rating. Note that the term ""U-factor"" (which redirects here) is usually used in the U.S. and Canada to express the heat flow through entire assemblies (such as roofs, walls, and windows). For example, energy codes such"
"this, glass fibre or ceramic are used. The measuring point, and usually most of the leads, require a housing or protective sleeve, often made of a metal alloy that is chemically inert to the process being monitored. Selecting and designing protection sheaths can require more care than the actual sensor, as the sheath must withstand chemical or physical attack and provide convenient attachment points. The simplest resistance-thermometer configuration uses two wires. It is only used when high accuracy is not required, as the resistance of the connecting wires is added to that of the sensor, leading to errors of measurement."
"an overall value of 0.006-0.008 W/(m·K) after allowing for thermal bridging (heat conduction across the panel edges) and the inevitable gradual loss of vacuum over time. The thermal resistance of VIPs ""per unit thickness"" compares very favourably to conventional insulation. For instance, standard mineral wool has a thermal conductivity of 0.044 W/(m·K), and rigid polyurethane foam panels about 0.024 W/(m·K). This means that VIPs have about one-fifth the thermal conductivity of conventional insulation, and therefore about five times the thermal resistance (R-value) per unit thickness. Based on a typical ""k""-value of 0.007 W/(m·K), the R-value of a typical 25 mm-thick"
"of resilience, ""σ"" is the yield strength, ""ε"" is the yield strain, and ""E"" is the Young's modulus. This analysis is not valid for non-linear elastic materials like rubber, for which the approach of area under the curve till elastic limit must be used. Resilience (""U"") is measured in a unit of joule per cubic meter (J·m) in the SI system, ""i.e."" elastical deformation energy per surface of test specimen (merely for gauge-length part). Like the unit of tensile toughness (""U""), the unit of resilience can be easily calculated by using area underneath the stress–strain (""σ""–""ε"") curve, which gives resilience"
"Thermal conductivity is conventionally defined as the rate of thermal conduction through a material per unit area per unit thickness per unit temperature differential (ΔT). The inverse of conductivity is resistivity (or R per unit thickness). Thermal conductance is the rate of heat flux through a unit area at the installed thickness and any given ΔT. Experimentally, thermal conduction is measured by placing the material in contact between two conducting plates and measuring the energy flux required to maintain a certain temperature gradient. For the most part, testing the R-value of insulation is done at a steady temperature, usually about"
"fibers—including Vectran. Woven materials, like Dacron, may specified as either high or low ""tenacity"", as indicated, in part by their denier count (a unit of measure for the linear mass density of fibers). High-tenacity Dacron comes in multiples of 220, 350 and 570 deniers, whereas low-tenacity Dacron comes in multiples of 150, 250, and 400 deniers. Sailcloth is typically heat-shrunk to tighten the weave and then receives a chemical bonding finish of melamine. Such cloth is typically specified by deniers for warp and fill (weft), e.g. 220/570. Conventional sails comprise panels, which are most often stitched together, at other times"
"on this topic. In general, works using the term ""thermal resistance"" are more engineering-oriented, whereas works using the term thermal conductivity are more [pure-]physics-oriented. The following books are representative, but may be easily substituted. Thermal resistance Thermal resistance is a heat property and a measurement of a temperature difference by which an object or material resists a heat flow. Thermal resistance is the reciprocal of thermal conductance. Absolute thermal resistance is the temperature difference across a structure when a unit of heat energy flows through it in unit time. It is the reciprocal of thermal conductance. The SI units of"
"would be to solve for resistivity as a function of applied voltage and current, as given in Equation () below: Resistivity is the electrical resistance of a dust sample 1.0 cm in cross-sectional area, 1.0 cm thick, and is recorded in units of ohm-cm. A method for measuring resistivity will be described in this article. The table below, gives value ranges for low, normal, and high resistivity. Resistance affects electrical conditions in the dust layer by a potential electric field (voltage drop) being formed across the layer as negatively charged particles arrive at its surface and leak their electrical charges"
"Wire Flammability Test (GWFI) and Comparative Tracking Index (CTI). Main applications are in the electrical and electronics (E&E) industry. Polybutylene terephthalate Polybutylene terephthalate (PBT) is a thermoplastic engineering polymer that is used as an insulator in the electrical and electronics industries. It is a thermoplastic (semi-)crystalline polymer, and a type of polyester. PBT is resistant to solvents, shrinks very little during forming, is mechanically strong, heat-resistant up to (or with glass-fibre reinforcement) and can be treated with flame retardants to make it noncombustible. PBT is closely related to other thermoplastic polyesters. Compared to PET (polyethylene terephthalate), PBT has slightly lower"
"Martindale (unit) The Martindale is a unit for quantifying the abrasion resistance of textiles, especially when used for upholstery. The Martindale method, also known as the Martindale rub test, simulates natural wear of a seat cover, in which the textile sample is rubbed against a standard abrasive surface with a specified force. The test equipment works in intervals of 5000 cycles, totalling the ""wear number"" (unit: Martindale) of abrasion cycles that leads to the material being worn to a specified degree. The higher the value, the more resistant the material is to abrasion. The national German textile institute specifies a"
"device (unit watts) and the device's thermal resistance (°C / Watt). A device that dissipates 0.5 W and has a thermal resistance of 12 K/W will have its temperature rise 6 °C above the ambient temperature. When Kelvin–Varley dividers are used to test high voltages, self-heating can create a problem. The first divider stage is often made from 10 kΩ resistors, so the divider input resistance is 100 kΩ. Total power dissipation at 1000 V is therefore 10 W. Most of the divider resistors will dissipate 1 W, but the two resistors bridged by the second divider stage will only"
"as silicone and fluorosilicone have low tear resistance. The ratio of tear resistance to the yield strength is called the tear-yield ratio. It is a measure of notch toughness. Tear resistance Tear resistance (or tear strength) is a measure of how well a material can withstand the effects of tearing. It is a useful engineering measurement for a wide variety of materials by many different test methods. For example with rubber, tear resistance measures how the test specimen resists the growth of any cuts when under tension, it is usually measured in kN/m. Tear resistance can be measured by the"
"in ounces per square foot. Thicknesses commonly used in construction in the U.S. are between 12ounces and 48 ounces. Since the industry often uses gauge numbers or actual thicknesses for sheet metal or other building materials, it is necessary to convert between the different measurement systems. In Europe, phosphorus de-oxidized non-arsenical copper is used with the designation C106. The copper is rolled to thicknesses ranging between 0.5 and 1.0 millimeters (1.5 - 3.0 millimeters for curtain walling) but a 0.6 - 0.7 millimeters thickness is usually used for roofing. Alloyed copper. Copper alloys, such as brass and bronze, are also"
"three main categories of RTD sensors are thin-film, wire-wound, and coiled elements. While these types are the ones most widely used in industry, other more exotic shapes are used; for example, carbon resistors are used at ultra-low temperatures (−173 °C to −273 °C). The current international standard that specifies tolerance and the temperature-to-electrical resistance relationship for platinum resistance thermometers (PRTs) is IEC 60751:2008; ASTM E1137 is also used in the United States. By far the most common devices used in industry have a nominal resistance of 100 ohms at 0 °C and are called Pt100 sensors (""Pt"" is the symbol"
"of Digital Thermometer Resistance temperature detectors (RTDs) RTDs are wire windings or other thin film serpentines that exhibit changes in resistance with changes in temperature.They measure temperature using the positive temperature coefficient of electrical resistance of metals. The hotter they become, the higher the value of their electrical resistance. Platinum is the most commonly used material because it is nearly linear over a wide range of temperatures, is very accurate, and has a fast response time. RTDs can also be made of copper or nickel. o Advantages of RTDs include their stable output for long periods of time. They are"
"scattering and thus basically independent of temperature. As a result, the sensitivity of the RTD is essentially zero and therefore not useful. Compared to thermistors, platinum RTDs are less sensitive to small temperature changes and have a slower response time. However, thermistors have a smaller temperature range and stability. The two most common ways of measuring temperatures for industrial applications are with resistance temperature detectors (RTDs) and thermocouples. Choice between them is usually determined by four factors. These elements nearly always require insulated leads attached. PVC, silicone rubber or PTFE insulators are used at temperatures below about 250 °C. Above"
"in the 0.1 to 6 range. The latter is similar, though run at much higher temperatures, to melt-blown thermoplastic nonwovens. Wet laid mat is almost always wet resin bonded with a curtain coater, while batts are usually spray bonded with wet or dry resin. An unusual process produces polyethylene fibrils in a Freon-like fluid, forming them into a paper-like product and then calendering them to create Tyvek. Both staple and spunlaid nonwovens would have no mechanical resistance in and of themselves, without the bonding step. Several methods can be used: The industry has attempted to define ""flushability"". They encourage voluntary"
"Megohmmeter Megohmmeter or megger is a special type of ohmmeter used to measure the electrical resistance of insulators. Insulating components, for example cable jackets, must be tested for their insulation strength at the time of commissioning and as part of maintenance of high voltage electrical equipment and installations. For this purpose megohmmeters, which can provide high DC voltages (typically in ranges from 500 V to 5 kV, some are up to 15 kV) at specified current capacity, are used. Acceptable insulator resistance values are typically 1 to 10 megohms, depending on the standards referenced. Resistance to be measured is connected"
"refers to the weight, not the strength, of the fabric. Laboratory tests have shown that double weave 1050 denier fabric is the strongest and most durable fabric for its denier weight level. The 1680 denier has a similar strength but lighter weight than the 1050, and it resists abrasion and tearing. Ballistic nylon is hard to dye, so it is often found in black or similar dark colors. Ballistic nylon Ballistic nylon is a thick, tough, nylon fabric with several uses. Ballistic nylon was developed by the DuPont corporation as a material for flak jackets to be worn by World"
"for platinum, ""100"" for the resistance in ohms at 0 °C). It is also possible to get Pt1000 sensors, where 1000 is for the resistance in ohms at 0 °C. The sensitivity of a standard 100 Ω sensor is a nominal 0.385 Ω/°C. RTDs with a sensitivity of 0.375 and 0.392 Ω/°C, as well as a variety of others, are also available. Resistance thermometers are constructed in a number of forms and offer greater stability, accuracy and repeatability in some cases than thermocouples. While thermocouples use the Seebeck effect to generate a voltage, resistance thermometers use electrical resistance and require"
"be split into the width formula_5 and the sheet thickness formula_6. Upon combining the resistivity with the thickness, the resistance can then be written as where formula_8 is the sheet resistance. If the film thickness is known, the bulk resistivity formula_2 (in Ω·cm) can be calculated by multiplying the sheet resistance by the film thickness in cm: Sheet resistance is a special case of resistivity for a uniform sheet thickness. Commonly, resistivity (also known as bulk resistance, specific electrical resistance, or volume resistivity) is in units of Ω·m, which is more completely stated in units of Ω·m/m (Ω·area/length). When divided"
"current through it. A thermocouple or resistance thermometer (RTD) can then be used to measure the temperature of the filament. This temperature is dependent on the rate at which the filament loses heat to the surrounding gas, and therefore on the thermal conductivity. A common variant is the Pirani gauge, which uses a single platinum filament as both the heated element and RTD. These gauges are accurate from 10 Torr to 10 Torr, but their calibration is sensitive to the chemical composition of the gases being measured. A Pirani gauge consist of a metal wire open to the pressure being"
"as ASHRAE 90.1 and the IECC prescribe U-values. However, R-value is widely used in practice to describe the thermal resistance of insulation products, layers, and most other parts of the building enclosure (walls, floors, roofs). Other areas of the world more commonly use U-value/U-factor for elements of the entire building enclosure including windows, doors, walls, roof, and ground slabs. The SI (metric) unit of R-value is whereas the I-P (inch-pound) unit is For R-values there is no difference between US customary units and imperial units, so the same I-P unit is used in both. Some sources use ″RSI″ when referring"