Scope: Details test and examination criteria for flammable vapor sensor systems and components for use in gas-burning appliances. This standard applies to a flammable vapor sensor or system capable of operating throughout a temperature range of 32oF (0o

定价： 4004元 / 折扣价： 3404 元

定价： 683元 / 折扣价： 581 元

4.1 Linear displacement sensor systems play an important role in orthopedic applications to measure micromotion during simulated use of joint prostheses.4.2 Linear displacement sensor systems must be calibrated for use in the laboratory to ensure reliable conversions of the system’s electrical output to engineering units.4.3 Linear displacement sensor systems should be calibrated before initial use, at least annually thereafter, after any change in the electronic configuration that employs the sensor, after any significant change in test conditions using the sensor that differ from conditions during the last calibration, and after any physical action on the sensor that might affect its response.4.4 Verification of sensor performance in accordance with calibration should be performed on a per use basis both before and after testing. Such verification can be done with a less accurate standard than that used for calibration, and may be done with only a few points.4.5 Linear displacement sensor systems generally have a working range within which voltage output is linearly proportional to displacement of the sensor. This procedure is applicable to the linear range of the sensor. Recommended practice is to use the linear displacement sensor system only within its linear working range.1.1 This practice covers the procedures for calibration of linear displacement sensors and their corresponding power supply, signal conditioner, and data acquisition systems (linear displacement sensor systems) for use in measuring micromotion. It covers any sensor used to measure displacement that gives an electrical voltage output that is linearly proportional to displacement. This includes, but is not limited to, linear variable differential transformers (LVDTs) and differential variable reluctance transducers (DVRTs).1.2 This calibration procedure is used to determine the relationship between output of the linear displacement sensor system and displacement. This relationship is used to convert readings from the linear displacement sensor system into engineering units.1.3 This calibration procedure is also used to determine the error of the linear displacement sensor system over the range of its use.1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 515元 / 折扣价： 438 元 加购物车

5.1 This test method is primarily used to monitor the concentration of oxygen in gases to verify gas quality for operational needs and contractual obligations. Oxygen content is a major factor influencing internal corrosion, fuel quality, gas quality, and user and operator safety.1.1 This test method is for the determination of oxygen (O2) in gaseous fuels and fuel type gases. It is applicable to the measurement of oxygen in natural gas and other gaseous fuels. This method can be used to measure oxygen in helium, hydrogen, nitrogen, argon, carbon dioxide, mixed gases, process gases, and ambient air. The applicable range is 0.1 ppm(v) to 25 % by volume.1.2 Units—The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 515元 / 折扣价： 438 元 加购物车

Clay elements are widely used in aviation fuel handling systems to adsorb polar contaminants that are picked up in shipments by tanker, barge, or pipeline from refineries to terminals, airports, or both. Some of these contaminants such as surfactants interfere with efficient operation of filter-separator units that remove water from fuel.In order to determine whether the clay elements are spent, it is necessary to test fuel both into and out of clay treatment vessels frequently. Clay elements must be changed when no improvement in quality is noted. Unless carried out frequently, such testing may not disclose a deactivated clay treatment vessel in time to prevent failure of downstream filter/separators.To avoid such failures, a small sample of clay in a clay holder contained in a sidestream installation that receives flow proportional to the main stream flow is evaluated periodically using a reference fuel containing a known surfactant. When the rating of the reference fuel by Test Method D 3948 indicates that the capsule clay is becoming spent, the elements in the main filter vessel are ready for change.1.1 This practice describes a field procedure to determine whether the useful life of the clay has been exceeded in canister or bag-type clay elements that are installed in ground filtration units of aviation fuel handling systems.1.2 The field procedure utilizes the apparatus of Test Methods D3948 to periodically test a small clay capsule installed in a sidestream around a clay treatment vessel that receives a fixed ratio of the same fuel that flows through the clay elements in the vessel.1.3 The values stated in SI units are to be regarded as standard. The inch-pound units in parentheses are for information only.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

定价： 0元 / 折扣价： 0 元

4.1 In neutron dosimetry, a fission or non-fission dosimeter, or combination of dosimeters, can be used for determining a fluence rate, fluence, or neutron spectrum in nuclear reactors. Each dosimeter is sensitive to a specific energy range, and, if desired, increased accuracy in a fluence-rate spectrum can be achieved by the use of several dosimeters each covering specific neutron energy ranges.4.2 A wide variety of detector materials is used for various purposes. Many of these substances overlap in the energy of the neutrons which they will detect, but many different materials are used for a variety of reasons. These reasons include available analysis equipment, different cross sections for different fluence-rate levels and spectra, preferred chemical or physical properties, and, in the case of radiometric dosimeters, varying requirements for different half-life isotopes, possible interfering activities, and chemical separation requirements.1.1 This guide covers the selection, design, irradiation, post-irradiation handling, and quality control of neutron dosimeters (sensors), thermal neutron shields, and capsules for reactor surveillance neutron dosimetry.1.2 The values stated in SI units are to be regarded as standard. Values in parentheses are for information only.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 590元 / 折扣价： 502 元 加购物车

5.1 This practice provides a means for the users of ASTM Committee D02 standards to monitor the drift in sensed temperature of liquid-in-glass thermometer (LiG), and digital contact thermometers (DCT). Digital contact thermometers are sometimes referred to as portable electronic thermometers (PET) or simply digital thermometers.5.2 This practice is not suitable for determining the accuracy or calibration of a temperature-measuring device as the error in the ice bath temperature can be greater than 0.02 °C. For greater accuracy, the user should use Practice E563 to prepare the ice bath.5.3 The ice point is a common practical industrial reference point of thermometry. The ice point is relatively simple to realize and provides a readily available natural fixed-point reference temperature.5.4 This practice only checks the measurement drift at a single temperature. It will not detect a change in measurement response with change in temperature. Temperature-measuring devices should be recalibrated at set intervals. See device supplier for recommendations.5.5 This practice provides a technique to determine minimum immersion depth of the sensing probe of the thermometer using an ice bath. The minimum immersion depth determined by this practice may change when the differential temperature differs significantly from the conditions described. A greater differential will likely increase the minimum immersion depth.1.1 This practice describes two procedures for use with temperature measurement devices. Methodology is described for determining minimum immersion depth for thermal sensors, in particular RTDs or similar temperature sensors. Included is a procedure for consistently preparing a reference bath for the purpose of monitoring measurement drift of thermal sensors such as liquid-in-glass or digital contact thermometers.1.2 This practice focuses on temperature measurement drift in a laboratory. If the user requires greater measurement accuracy, then they should follow the instructions in Practice E563.1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 515元 / 折扣价： 438 元 加购物车

4.1 This practice is intended for the application of in-line, full-flow inductive wear debris sensors. According to (1), passing the entire lubrication oil flow for aircraft and aero-derivative gas turbines through a debris-monitoring device is a preferred approach to ensure sufficient detection efficiency.4.2 Periodic sampling and analysis of lubricants have long been used as a means to determine overall machinery health (2). The implementation of smaller oil filter pore sizes for machinery operating at higher rotational speeds and energies has reduced the effectiveness of sampled oil analysis for determining abnormal wear prior to severe damage. In addition, sampled oil analysis for equipment that is remote or otherwise difficult to monitor or access is not practical. For these machinery systems, in-line wear debris sensors can be very useful to provide real-time and near-real-time condition monitoring data.4.3 In-line full-flow inductive debris sensors have demonstrated the capability to detect and quantify both ferromagnetic and non-ferromagnetic metallic wear debris. These sensors record metallic wear debris according to size, count, and type (ferromagnetic or non-ferromagnetic). Sensors are available for a variety of oil pipe sizes. The sensors are designed specifically for the protection of rolling element bearings and gears in critical machine applications. Bearings are key elements in machines since their failure often leads to significant secondary damage that can adversely affect safety, operational availability, or operational/maintenance costs, or a combination thereof.4.4 The main advantage of the sensor is the ability to detect early bearing damage and to quantify the severity of damage and rate of progression of failure towards some predefined bearing surface fatigue damage limiting wear scar. Sensor capabilities are summarized as follows:4.4.1 In-line full flow non-intrusive inductive metal detector with no moving parts.4.4.2 Detects both ferromagnetic and non-ferromagnetic metallic wear debris.4.4.3 Detects 95 % or more of metallic wear debris above some minimum particle size threshold.4.4.4 Counts and sizes wear debris detected.4.5 Fig. 1 presents a widely used diagram (2) to describe the progress of metallic wear debris release from normal to catastrophic failure. It must be pointed out that this figure summarizes metallic wear debris observations from all the different wear modes that can range from polishing, rubbing, abrasion, adhesion, grinding, scoring, pitting, spalling, etc. As mentioned in numerous references (1-11), the predominant failure mode of rolling element bearings is spalling or macro pitting. When a bearing spalls, the contact stresses increase and cause more fatigue cracks to form within the bearing subsurface material. The propagation of existing subsurface cracks and creation of new subsurface cracks causes ongoing deterioration of the material that causes it to become a roughened contact surface as illustrated in Fig. 2. This deterioration process produces large numbers of metallic wear debris with a typical size range from 100 to 1000 microns or greater. Thus, rotating machines, such as gas turbines and transmissions, which contain rolling element bearings and gears made from hard steel tend to produce this kind of large metallic wear debris that eventually leads to failure of the machines.FIG. 1 Wear Debris CharacterizationFIG. 2 Typical Bearing Spall4.6 In-line wear debris monitoring provides a more reliable and timely indication of bearing distress for a number of reasons:4.6.1 Firstly, bearing failures on rotating machines tend to occur as events often without sufficient warning and could be missed by means of only periodic inspections or data sampling observations.4.6.2 Secondly, since it is the larger wear metallic debris that are being detected, there is a lower probability of false indication from the normal rubbing wear that will be associated with smaller particles.4.6.3 Thirdly, build or residual debris from manufacturing or maintenance actions can be differentiated from actual damage debris because the cumulative debris counts recorded due to the former tend to decrease while those due to the latter tend to increase.4.6.4 Fourthly, bearing failure tests have shown that wear debris size distribution is independent of bearing size. (2-5) and (11).1.1 This practice covers the minimum requirements for an in-line, non-intrusive, through-flow oil debris monitoring system that monitors ferromagnetic and non-ferromagnetic metallic wear debris from both industrial aero-derivative and aircraft gas turbine engine bearings. Gas turbine engines are rotating machines fitted with high-speed ball and roller bearings that can be the cause of failure modes with high secondary damage potential. (1)21.2 Metallic wear debris considered in this practice range in size from 120 μm (micron) and greater. Metallic wear debris over 1000 μm are sized as over 1000 μm.1.3 This practice is suitable for use with the following lubricants: polyol esters, phosphate esters, petroleum industrial gear oils and petroleum crankcase oils.1.4 This practice is for metallic wear debris detection, not cleanliness.1.5 The values stated in SI units are to be regarded as standard. The values given in parentheses are provided for information only.1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 646元 / 折扣价： 550 元 加购物车

3.1 Degradation in sensor performance can occur due to dropping, mechanical shock while mounted on the test structure, temperature cycles, and so forth. It is necessary and desirable to have a simple measurement procedure that will check the consistency of sensor response, while holding all other variables constant.3.2 While test blocks of many different kinds have been used for this purpose for many years, an acrylic polymer rod offers the best all-around combination of suitable acoustic properties, practical convenience, ease of procurement and low cost.3.3 Because the acoustic properties of the acrylic rod are known to depend on temperature, this practice requires that the rod, sensors, and couplant be stabilized at the same working temperature, prior to verifying the sensors.3.4 Attention should be paid to storage conditions for the acrylic polymer rod. For example, it should not be left in a freezing or hot environment overnight, unless it is given time for temperature stabilization before use.3.5 Properly applied and with proper record keeping, this practice can be used in many ways. The user organization must determine the context for its use, the acceptance standards and the actions to be taken based on the lead break results. The following uses are suggested:3.5.1 To determine when a sensor is no longer suitable for use.3.5.2 To check sensors that have been exposed to high-risk conditions, such as dropping, overheating, and so forth.3.5.3 To get an early warning of sensor degradation over time. This can lead to identifying conditions of use, which are damaging sensors, and thus, to better equipment care and lower replacement costs.3.5.4 To obtain matched sets of sensors, preamplifiers, instrumentation channels, or a combination thereof, for more uniform performance of the total system.3.5.5 To save time and money, by eliminating the installation of bad sensors.3.5.6 To verify sensors quickly but consistently in the field and to assist trouble-shooting when a channel does not pass a performance check.FIG. 1 Acrylic Rod Description3.6 All the above uses are recommended for consideration. The purpose of this practice is not to call out how these uses are to be implemented, but only to state how the test itself is to be performed so that the results obtained will be accurate and reliable.1.1 This practice is used for routinely checking the sensitivity of acoustic emission (AE) sensors. It is intended to provide a reliable, precisely specified way of comparing a set of sensors, or telling whether an individual sensor's sensitivity has degraded during its service life, or both.1.2 This practice is not a “calibration” nor does it give frequency response information.1.3 Units—The values stated in SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 590元 / 折扣价： 502 元 加购物车

5.1 Eddy current methods are used for nondestructively locating and characterizing discontinuities and geometric property variations in magnetic or nonmagnetic electrically conducting materials. Conformable eddy current sensor arrays permit examination of planar and non-planar materials but usually require suitable fixtures to hold the sensor array near the surface of the material of interest, such as a layer of foam behind the sensor array along with a rigid support structure.5.2 In operation, the sensor arrays are standardized with measurements in air or a reference part, or both. Responses measured from the sensor array may be converted into physical property values, such as lift-off, electrical conductivity, or magnetic permeability, or a combination thereof. Proper instrument operation is verified by ensuring that these measurement responses or property values are within a prescribed range. Performance verification is performed periodically. Performance verification on a discontinuity-free reference standard or regions of the material being examined that do not contain discontinuities ensures that the electrical and geometric properties, such as electrical conductivity, layer thickness, or lift-off, or a combination thereof, are appropriate for the sensor array. Performance verification on a discontinuity-containing reference standard ensures that the sensor array response to the discontinuity is appropriate.5.3 The sensor array dimensions, including the size and number of sense elements, and the operating frequency are selected based on the type of examination being performed. The depth of penetration of eddy currents into the material under examination depends upon the frequency of the signal, the electrical conductivity and magnetic permeability of the material, and some dimensions of the sensor array. The depth of penetration is equal to the conventional skin depth at high frequencies but is also related to the sensor array dimensions at low frequencies, such as the size of the drive winding and the gap distance between the drive winding and sense element array. For surface-breaking discontinuities on the surface adjacent to the sensor array, high frequencies should be used where the penetration depth is less than the thickness of the material under examination. For subsurface discontinuities or wall thickness measurements, lower frequencies and larger sensor dimensions should be used so that the depth of penetration is comparable to the material thickness.5.4 Insulating layers or coatings may be present between the sensor array and the surface of the electrically conducting material under examination. The sensitivity of a measurement to a discontinuity generally decreases as the coating thickness or lift-off, or both, increases. For eddy current sensor arrays having a linear drive conductor and a linear array of sense elements, the spacing between the drive conductor and the array of sense elements should be smaller than or comparable to the thickness of the insulating coating. For other array formats the depth of sensitivity should be verified empirically.5.5 Models for the sensor response may be used to convert responses measured from the sensor array into physical property values, such as lift-off, electrical conductivity, magnetic permeability, coating thickness, or substrate thickness, or a combination thereof. For determining two property values, one operational frequency can be used. For nonmagnetic materials and examination for crack-like discontinuities, the lift-off and electrical conductivity should be determined. For magnetic materials, when the electrical conductivity can be measured or assumed constant, then the lift-off and magnetic permeability should be determined. The thickness can only be determined if a sufficiently low excitation frequency is used where the depth of sensitivity is greater than the material thickness of interest. For determining more than two property values, measurements at operating conditions having at least two depths of penetration should be used; these different depths of penetration can be achieved by using multiple operational frequencies or multiple spatial wavelengths.5.6 Processing of the measurement response or property value data may be performed to highlight the presence of discontinuities, to reduce background noise, and to characterize detected discontinuities. As an example, a correlation filter can be applied in which a reference signature response for a discontinuity is compared to the measured responses for each sensor array element to highlight discontinuity-like defects. Care must be taken to properly account for the effect of interferences such as edges and coatings on such signatures.5.7 The measurement and analysis methods described in this guide can also be applied to applications where the sensor array is mounted against a surface or embedded within the material being examined. In that situation the sensor array response is monitored over a period of time instead of the scanning the sensor array over a specific location. This leads to the horizontal axes for the B-scans and C-scans to correspond to time or some other input associated with the test such as the number of loading cycles.1.1 This guide covers the use of conformable eddy current sensor arrays for nondestructive examination of electrically conducting materials for discontinuities and material quality. The discontinuities include surface breaking and subsurface cracks and pitting as well as near-surface and hidden-surface material loss. The material quality includes coating or layer thickness, electrical conductivity, magnetic permeability, surface roughness, and other properties that vary with the electrical conductivity or magnetic permeability.1.2 This guide is intended for use on nonmagnetic and magnetic metals as well as composite materials with an electrically conducting component, such as reinforced carbon-carbon composite or polymer matrix composites with carbon fibers.1.3 This guide applies to planar as well as non-planar materials with and without insulating coating layers.1.4 Units—The values stated in SI units are to be regarded as standard. The values given in parentheses are mathematical conversions to inch-pound units that are provided for information only and are not considered standard.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 590元 / 折扣价： 502 元 加购物车

5.1 The OTR is an important determinant of the packaging protection afforded by barrier materials. It is not, however, the sole determinant, and additional tests, based on experience, must be used to correlate packaging performance with OTR. It is suitable as a referee method of testing, provided that the purchaser and the seller have agreed on sampling procedures, standardization procedures, test conditions, and acceptance criteria.5.2 Limited statistical data on correlations with Test Method D1434 methods are available4; however, the oxygen transmission rate of a standard reference material (see 12.1) as determined manometrically by NIST, is in good agreement with the values obtained in the coulometric interlaboratory test using material from the same manufacturing lot. Thus, this test method may be used as a referee method.1.1 This test method covers a procedure for determination of the steady-state rate of transmission of oxygen gas through plastics in the form of film, sheeting, laminates, coextrusions, or plastic-coated papers or fabrics. It provides for the determination of (1) oxygen gas transmission rate (OTR), (2) the permeance of the film to oxygen gas (PO2), and (3) oxygen permeability coefficient (P′O2) in the case of homogeneous materials.1.2 This test method does not purport to be the only method for measurement of OTR. There may be other methods of OTR determination that use other oxygen sensors and procedures.1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.4 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 590元 / 折扣价： 502 元 加购物车

4.1 An MFS has similar properties to a load cell or strain gauge. However, an MFS is not suitable for precision measurements.4.2 MFS pressure versus resistance data can be calculated if the force probe is providing uniform pressure over a distributed area or if the sensor is exposed to measurable air or hydraulic pressure.4.3 MFS force-resistance plotted results are not linear and results may change when exposed to repeated force cycles – Test Method F1578. It is useful to note that the force-resistance curve models closely to mathematical form of y = 1/x.4.4 Static forces may contribute to drifting test results (also known as creep).1.1 This test method covers the force versus resistance measurement of a membrane force sensor (MFS) where the electrical resistance decreases as the force on the sensor is increased.1.2 An MFS may or may not be electrically open in its static state. This depends on the attributes required for the application. If the MFS has a measureable resistance in static state, it was most likely designed to be used as a variable resistor, not as a normally open switch. A high but measurable resistance, in static state, may still be considered an open switch if the resistance is above the closed resistance threshold recognized by the interface electronics.1.3 Special printed conductive polymer inks or characteristics, or both, of the sensor design are used in MFS to achieve variable resistance when compressed. As force is applied to the MFS the resistance continues to decrease, but not linearly, until a point where additional force does not change the resistance appreciably. Ideally, when force is removed from the MFS the resistance will return to, or close to, its original value.1.4 Materials other than conductive polymers can be used in an MFS and also exhibit reduced resistance with increasing force.1.5 This test method should not be confused with Test Method F2592 for measuring the force-displacement characteristics of a membrane switch (MS) that is designed for momentary closure. Although the resistance of a MS does change during contact closure the change from high resistance to contact resistance is very sudden and additional force does not have a significant effect on the resistance; that is, an MS is not designed to be used as a variable resistor.1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 0元 / 折扣价： 0 元

5.1 This test method is intended for use as a control, acceptance, and assessment test.5.2 Moisture can seriously affect the processability of plastics. It is possible that high moisture content will cause surface imperfections (that is, splay or bubbling) or degradation by hydrolysis. Low moisture (with high temperature) has been known to cause solid phase polymerization.5.3 The physical properties of some plastics are greatly affected by the moisture content.1.1 This test method covers the quantitative determination of water down to 20 ppm in plastics using a relative humidity sensor.1.2 Values stated in SI units are to be regarded as standard.1.3 Specimens tested in this test method can reach or exceed 250°C, use caution when handling them after testing has completed.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.NOTE 1: There is no known ISO equivalent to this standard.1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 515元 / 折扣价： 438 元 加购物车

5.1 The purpose of this test method is to obtain reliable values for the WVTR of plastic film and sheeting.5.2 WVTR is an important property of packaging materials and can be directly related to shelf life and packaged product stability.5.3 Data from this test method is suitable as a referee method of testing, provided that the purchaser and seller have agreed on sampling procedures, standardization procedures, test conditions, and acceptance criteria.1.1 This test method covers a procedure for determining the rate of water vapor transmission through flexible barrier materials. The method is applicable to sheets and films consisting of single or multilayer synthetic or natural polymers and foils, including coated materials. It provides for the determination of water vapor transmission rate (WVTR).1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

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5.1 The heated diode sensor device used in this practice is selective for HVOCs. Other electronegative compounds, such as alcohols, ketones, nitrates, and sulfides, may cause a positive interference with the performance of the heated diode sensor to detect HVOCs, but to do so, they must be present at much higher concentrations than the HVOCs.NOTE 2: For volatile organic compound (VOC) screening purposes, a flame ionization detector (FID) selectively responds to flammable VOCs; a photoionization detector (PID) selectively responds to VOCs having a double bond; and a heated diode sensor selectively responds to halogenated VOCs.5.2 This practice can be used for screening media known to contain TCE to estimate the concentration of TCE in the media. Procedure A is to be used for screening soil known to contain TCE and Procedure B is to be used for screening water known to contain TCE. Both Procedures A and B involve measuring the TCE concentration in the headspace above a sample. From this measurement, an estimated concentration of TCE in the sample can be determined. Any TCE remaining in the sample is not measured by this practice. Any other HVOC present in the sample will be reported as TCE.5.3 This practice can also be used for screening the headspace above a soil or water suspected of containing HVOC contamination to indicate the presence or absence of HVOC contamination in the soil (Procedure A) or water (Procedure B). Any HVOC contamination remaining in the sample is not detected by this practice.5.4 Detection Limit—The detection limit of the heated diode sensor for TCE is 0.1 mg/m3 in air, based on a signal-to-noise ratio of 2. For a 25-g TCE-contaminated soil sample in a 250-mL container, the detection limit of Procedure A for TCE is 0.001 mg/Kg, assuming complete partitioning of TCE into the headspace. For a 25-g TCE-contaminated water sample in a 250-mL container, the detection limit of Procedure B for TCE is 0.001 mg/L, assuming complete partitioning of TCE into the headspace.5.5 This practice can be used to screen moist soil samples and water samples. Water vapor does not interfere with the performance of the heated diode sensor.5.6 Hydrocarbon fuels, including fuels containing aromatic compounds, such as gasoline, are not detected by the practice.1.1 This practice describes procedures for screening media known to contain the halogenated volatile organic compound (HVOC), trichloroethylene (TCE). Procedure A is to be used for screening soil known to contain TCE and Procedure B is to be used for screening water known to contain TCE.1.1.1 Both Procedures A and B involve measuring the TCE concentration in the headspace above a sample using a heated diode sensor device. From this measurement, an estimated concentration of TCE in the sample can be determined. Any TCE remaining in the sample is not measured. Any other HVOC present in the sample will be reported as TCE.1.2 Procedure A can also be used for screening the headspace above a soil suspected of containing HVOC contamination to indicate the presence or absence of HVOC contamination in the soil. Procedure B can also be used for screening the headspace above a water suspected of containing HVOC contamination to indicate the presence or absence of HVOC contamination in the water. For both procedures, any HVOC contamination remaining in the soil or water is not detected by this practice.1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.3.1 Exception—Certain inch-pound units are provided for information only.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health and environmental practices and determine the applicability of regulatory limitations prior to use.NOTE 1: The diode sensor is heated to temperatures ranging between approximately 600 and 1000 °C (see 6.1.5) and as a result could be a source of ignition.1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

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