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Process and temperature insensitive CMOS oscillator using current sinker compensation

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frequencies which are200,500,800,and1000MHz.The pat-terns are called divisive as they are consists of main lobes as shown in Figure7.The energy distributed is not equal which is right lobe is smaller in magnitude compared to the left lobes because some energy released has been absorbed by the resistor.4.CONCLUSIONBased on Refs.3,5,8,and9,the physical dimensions of the planar monopole antenna presented are considered small in size and broadband.This antenna is fed from the bottom of the patch.After a lot of parameter optimization routine,the compact size with optimum performance is obtained.By integrating50 dual bevel angle with a single100X resistor,the more current flow to the ground and the radiating element has become more magnetic.Thus,the proposed antenna achieved a very wideband impedance bandwidth of approximately more than200%.A pro-totype antenna was designed,fabricate and the performance measure is presented.The antenna has the ability to operate for the VHF and partial of UHF spectrum.Besides the targeted white spaces(broadcasting spectrum)is also catered by this antenna.This gives it more credit as a great choice for the CR applications in the future.ACKNOWLEDGMENTSThe authors thank the Government of Malaysia,Ministry of Sci-ence,Technology and Innovations for the funding(Vote79300) that enabled this work to be accomplished and also special thanks to the members of Wireless Communication Centre(WCC),Fac-ulty of Electrical Engineering,Universiti Teknologi Malaysia for their help and kindness.REFERENCES1.M.J.Marcus,Unlicensed cognitive sharing of TV spectrum:Thecontroversy at the federal communications commission,IEEE Commun Mag43(2005),24–25.2.J.R.Kelly,E.Ebrahimi,P.S.Hall,P.Gardner,and F.Ghanem,Combined wideband and narrowband antennas for radio applica-tions,In:Cognitive Radio and Software Defined Radios:Technolo-gies and Techniques,London,2008.3.W.-S.Lee,D.-Z.Kim,K.-J.Kim,and J.-W.Yu,Wideband planarmonopole antennas with dual band-notched characteristics,IEEE Trans Microwave Theory Tech54(2006),2800–2806.4.T.Chakravarty,S.M.Roy,S.K.Sanyal,and A.De,A novel micro-strip patch antenna with large impedance bandwidth in VHF/UHF range,Prog Electromagn Res54(2005),83–93.5.M.J.Ammann and Z.N.Chen,A wide-band shorted planar monop-ole with bevel,IEEE Trans Antennas Propag51(2003),901–903.6.J.Chu,C.Ruan,X.Liao,and Y.Cui,A small size broadbandantenna used in VHF/UHF band,Presented at the8th International Symposium on IEEE Antennas,Propagation and EM Theory, 2008.ISAPE2008.7.Y.Y.Kyi,L.Jianying,and G.Y.Beng,Study of broadband smallsize conical antenna,Presented at the IEEE Antennas and Propaga-tion Society International Symposium,Albuquerque,NM,2006. 8.M.T.Islam,M.N.Shakib,N.Misran,and T.S.Sun,Broadbandmicrostrip patch antenna,Eur J Sci Res27(2009),174–180.9.D.Y.Xia,H.Zhang, F.Z.Geng,and Q.Y.Zhang,A study ofsphere-loaded and dielectric-covered mono-conical antenna for broadband application,Presented at the IEEE Antennas and Propo-gation Society International Symposium,Albuquerque,NM,2006. V C2011Wiley Periodicals,Inc.PROCESS AND TEMPERATURE INSENSITIVE CMOS OSCILLATOR USING CURRENT SINKER COMPENSATIONM.Kim,1S.Jung,2and Y.Yang11School of Information and Communication Engineering, Sungkyunkwan University,Suwon440-746,Republic of Korea; Corresponding author:yang09@2Samsung Techwin,Sungnam,Republic of KoreaReceived25March2011ABSTRACT:This article presents a simple complementary metal-oxide-semiconductor(CMOS)ring oscillator using a voltage-controlled delay and RS-latch,including a compensation circuit for the process and temperature variations.The compensation circuit,added to the original bias circuit,is a simple current sinker which is referenced through a current mirror circuit.The proposed oscillator was designed and implemented using a0.13l m CMOS process.The oscillator exhibited a significantly improved frequency variation of64.25%for a wide temperature range of fromÀ40to80 C.Without the compensation circuit,the variation would have been613.39%from the center frequency of2.33MHz.The oscillator also showed a low sensitivity of 0.084%to process variation,according to a Monte-Carlo simulation with1000iterations.V C2011Wiley Periodicals,Inc.Microwave Opt Technol Lett54:160–163,2012;View this article online at .DOI10.1002/mop.26493Key words:oscillator;temperature compensation;CMOS1.INTRODUCTIONA clock generator in general provides analog,digital,or mixed-signal systems with a system clock[1].For precision clock gen-eration,a phase-locked loop(PLL)is ordinarily used[2–4].The PLL includes an off-chip temperature compensated crystal oscil-lator(TCXO)or even an oven-controlled crystal oscillator (OCXO)to supply a stable and accurate frequency reference[4]. Despite having an excellent precision in frequency over temper-ature variations,such compensation methods involve a complex circuit structure and require some external components.A slightly simpler method is the use of a frequency-locked loop (FLL)[5].This does not need an external oscillator for refer-ence,but the circuits are still very complex.Therefore,in some low-cost applications,which require mod-erate-precision clocks,fully integrated oscillators with an improved insensitivity in frequency over temperature or process variation can be adopted.Conventional CMOS oscillators have significant frequency variation mainly because of the carrier mo-bility and threshold voltage variations of the transistor according to the process or temperature variation[6,7].For this reason, many previous researchers have been attempting to design more insensitive oscillators[1,5,8–14].Except for PLL and FLL methods,which are too expensive for low-cost applications,many compensation schemes for tem-perature and/or process variations have been proposed[1,8–14]. Most of them are methods that use compensated bias circuits.A temperature compensation circuit based on a bias circuit with Vt sensing and its replica bias circuit has been proposed [1].This circuit exhibited an excellent compensation perform-ance but it still requires a complex compensation circuit.A sim-ple compensation circuit,based on a stack of PMOS and bipolar junction transistor(BJTs),was demonstrated with provide just a moderate compensation performance[9].In[12],a compensa-tion circuit with an adjustable current ratio was presented.It has a moderate compensation capability,but requires a verycomplex digital switching part.A reference voltage generator with a positive temperature coefficient using two OP amps was proposed in [13].A good performance was reported,but the cir-cuits involved were significantly complex.A method using a con-stant gm bias and its replica circuit was presented in [14].This approach provides a moderate complexity and performance.In this article,a simple CMOS ring oscillator using voltage-controlled delays (VCDs)and an RS-latch,including a compen-sation circuit based on simple current mirror,is proposed for low-end clock generators.Though the proposed compensationcircuit has a simpler structure than those described in previous works [1,8–14],it has comparable or even better compensation capability over a wide temperature range.This circuit consists of PMOS and NMOS diodes which pro-vide an appropriate reference voltage for an NMOS current sinker according to the process and temperature variations.For a reduced variation of the oscillation frequency,theNMOSFigure 1Schematic diagram of the CMOS oscillator with VCDs and anRS-latchFigure 2Simulation results (a)Oscillation frequencies according to the varying control voltages for VCD as parameters of temperature.(b)Required control voltages to have a fixed oscillation frequency overtemperatureFigure 3Proposed compensation circuit with an NMOS currentsinkerFigure 4Simulation results (a)Simulated control voltages,V1.(b)Oscillation frequencies according to the temperature with and without the compensation circuitcurrent sinker diverts an appropriate amount of current accord-ing to the temperature from the original bias circuit of the oscillator.For verification,the ring oscillators with and without the compensation circuit were designed and implemented using a 0.13l m CMOS process.Temperature variation was measured and compared for both oscillators.Monte-Carlo simulation was used to evaluate the process variation.2.CIRCUIT DESIGN2.1.CMOS OscillatorFigure 1shows a schematic diagram of the CMOS ring oscilla-tor based on VCD circuits and an RS-latch.The oscillator also consists of a simple bias circuit,which supplies a control volt-age of V1to the VCD blocks,and has two buffer stages.The voltage V1controls the delay of each VCD block so that the os-cillation frequency is determined.The oscillation frequency is directly changed by the delay variation of the VCD which is controlled by V1.Conversely,the oscillation frequency,which tends to vary for the process and temperature variations,can be fixed by appropriately chang-ing V1.Therefore,the VCD needs a compensated bias circuit to have an adjustable control voltage of V1against the environ-mental changes.On the basis of the schematic diagram of the oscillator,shown in Figure 1,a 2.33MHz CMOS ring oscillator,including VCDs and an RS-latch,was initially designed.Figure 2(a)shows oscil-lation frequencies according to the varying control voltages for the VCD at various temperatures.If an application requires a clock generator to operate with an oscillation frequency of 2.33MHz,the clock generator has to include a bias circuit with a con-trol voltage range of approximately from 0.45to 0.85V.Figure 2(b)is a plot for the extracted control voltages to have a fixed os-cillation frequency over a temperature ranges from À40to 80 pensation CircuitFigure 3shows the proposed compensation circuit which is composed of a reference generator and an NMOS current sinker.Both are adjusted by each degeneration resistor,R2and R3,respectively.Another reference voltage,V2,in the compensation circuit is generated by the reference circuit using M5,M6,and R2,which has exactly the same configuration with the reference circuit as used for V1.Controlled by V2,the current sinker,based on M8and R3,diverts the compensation current (Icomp)from the original bias circuit through which flows a current,I1.The simulated control voltages,V1,with and without the compensation circuits are shown in Figure 4.As shown,the voltage curve of V1without the compensation circuit is significantly steeper than the required control voltage curve over the temperature range of interest.If voltage V1increases as the temperature increases,the volt-age V2in the compensation circuit also increases.The increased voltage,V2,diverts more current Icomp,so that thecontrolFigure 5Layout of the CMOS oscillator with the compensationcircuitFigure 6Simulated and measured oscillation frequencies overtemperatureFigure 7Monte-Carlo simulation results of the designed oscillators with and without the compensation circuitTABLE 1Performance SummaryW/O CompensationW/CompensationFrequency (MHz)2.33Temperature range ( C)À40to 80Power consumption (l W) 2.182.19Size (l m 2)125.51Â89.34138.22Â90.62Freq.variation (%)over temp.613.3964.25Process sensitivity (r /l )(%)0.1320.084r ,standard deviation;l ,average frequency.voltage,V1,decreases.This negative feedback behavior of the temperature compensation circuit allows the control voltage,V1, to have aflatter oscillation frequency response over the tempera-ture range,as shown in Figure4(b).A little mismatch in the voltage in the high temperature region after compensation does not cause much change in frequency.Degeneration resistors of R2and R3are used to optimize the level of compensation in terms of the oscillation frequency.3.EXPERIMENTAL RESULTSThe CMOS ring oscillator with the proposed temperature com-pensation circuit is designed and fabricated using Samsung’s 0.13l m commercial CMOS process.Figure5shows the layout of the proposed oscillator with a size of138.22Â90.62l m2. The implemented IC was evaluated with a bias supply of1.15V with a very low current consumption of as low as1.91l A.Figure6shows the simulated and measured oscillation fre-quencies according to the temperature variations.The proposed oscillator with the compensation circuit has a significantly smaller frequency variation of8.5%from the center frequency, whilst the same oscillator used without the compensation circuit has a frequency variation of26.79%over the wide temperature range ofÀ40to80 C.To check the performance of the compensation circuit over the process variation,a Monte-Carlo simulation with1000itera-tions was carried out using Cadence’s Spectre.Figure7shows the resultant statistical distributions:in terms of the number of samples per each10kHz step.It is clearly shown that the pro-posed oscillator with the compensation circuit has a sharper and taller histogram which guarantees a better yield in the presence of process variation.The proposed oscillator with the compensa-tion circuit has a significantly smaller process sensitivity of 0.084%,whilst the oscillator without compensation has a process sensitivity of about0.132%.The process sensitivity is obtained using a standard deviation over its average frequency(r/l).Table1summarizes the performances of the implemented oscillator ICs with and without the proposed compensation cir-cuit.Table2compares the performances of the proposed oscilla-tor with those obtained from previously published work.4.CONCLUSIONSIn this article,a temperature and process insensitive CMOS os-cillator with a very simple compensation circuit is proposed. The compensation circuit,which is added to the original bias circuit,is just a current sinker referenced using a current mirror.The proposed oscillator was implemented using a commer-cial0.13l m CMOS process.The performance of the oscillator was measured and compared with the performance achievable without the compensation circuit.As a result,the proposed CMOS oscillator was found to exhibit a very small frequency variation of64.25%from the center frequency,whilst the same oscillator without compensation showed a variation of613.39% across the temperature variation of fromÀ40to80 C.The oscillator also displayed a significantly improved process sensitivity of0.084%at an average frequency of2.33MHz,which was simulated using a Monte-Carlo simulation with1000itera-tions.The proposed oscillator can be applied to realize a number of different low-cost and low-end clock generator designs. ACKNOWLEDGMENTSThis work was supported by National Research Foundation of Korea Grant funded by the Korean Government(2009-0067097).REFERENCES1.K.Sundaresan,P.E.Allen,and F.Ayazi,Process and temperaturecompensation in a7-MHz CMOS clock oscillator,IEEE J Solid--State Circuits41(2006),433–442.2.H.Ma,X.Tang,T.Wu,and Z.Cao,New method to design a low-phase-noise millimeter-wave PLL frequency synthesizer,Micro-wave Opt Technol Lett48(2006),1194–1197.3.F.Plessas and G.Kalivas,A5-GHz injection-locked phase-lockedloop,Microwave Opt Technol Lett46(2005),80–84.4.H.Chen,E.Lee,and R.Geiger,A2-GHz VCO with process andtemperature compensation,In:Proceedings of IEEE International Symposium Circuits and Systems2,1999,pp.569–572.5.K.Ueno,T.Asai,and Y.Amemiya,A30-MHz,90-ppm/C fully-integrated clock reference generator with frequency-locked loop, In:Proceedings of ESSCIRC,2009,pp.392–395.6.F.Fiori and P.S.Crovetti,A new compact temperature-compen-sated CMOS current reference,IEEE Trans Circuits and Systems 52(2005),724–728.7.R.Kumar and V.Kursun,Voltage optimization for temperature vari-ation insensitive CMOS circuits,Presented at the IEEE International Midwest Symposium Circuits and Systems1,2005,pp.476–479. 8.K.Kato,T.Sase,and H.Sato,A low-power128-MHz VCO formonolithic PLL IC’s,IEEE J Solid-State Circuits23(1988), 474–479.9.Y.-S.Shyu and J.-C.Wu,A process and temperature compensatedring oscillator,Presented at the IEEE Asia Pacific ASIC Confer-ence,1999,pp.283–286.10.T.S.Cheung,H.Wong,and Y.C.Cheng,250MHz NMOS relaxa-tion oscillator with enhanced linear voltage-frequency characteristic and temperature stability,Electron Lett28(1992),1917–1919. 11.D.-S.Min,S.Cho,D.S.Jun,D.-J.Lee,Y.Seok,and D.Chin,Temperature-compensation circuit techniques for high-density CMOS DRAM’s,IEEE J Solid-State Circuits27(1992),626–631.12.U.Denier,Analysis and design of an ultralow-power CMOS relax-ation oscillator,IEEE Trans Circuits and Systems I57(2010), 1973–1982.13.G.D.Vita,F.Marraccini,and G.Iannaccone,Low-voltage low-power CMOS oscillator with low temperature and process sensitiv-ity,Presented at the IEEE International Symposium Circuits and Systems,2007,pp.2152–2155.kshmikumar,V.Mukundagiri,and S.L.J.Gierkink,A pro-cess and temperature compensated two-stage ring oscillator,Pre-sented at the IEEE Custom Integrated Circuits Conference,2007, pp.691–694.V C2011Wiley Periodicals,Inc.TABLE2Performance Comparison[1][9][12][13][14]This Work Process(l m)0.250.60.350.350.130.13 Oscillation frequency7.02MHz680KHz 3.3KHz80KHz 1.25GHz 2.33MHz Temperature range( C)À40to12535to1350to700to80À40to120À40to80 Frequency variation(%)60.8464.765.563.4765.064.25Structure Vtsensing StackedPMOSand BJTAdjustablecurrent ratioFeedbackusing twoOP-AmpsConstant gmand its replicaCurrentsinker。

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专业英语


Definition of polymers A simple understanding of polymers can be gained by imaging them to be like a chain or, perhaps, a string of pearls, where the individual pearl represent small molecules that are chemically bonded together. Therefore, a polymer is a molecule made up of smaller molecules that are joined together by chemical bonds. The word polymer means „many parts or units.‟ The parts or units are the small molecules that combine. The result of the combination is, of course, a chainlike molecule (polymer). Usually the polymer chains are long, often consisting of hundreds of units, but polymers consisting of only a few units linked together are also known and can be commercially valuable.
Figure 1.1 Diagram illustrating the definition of plastics.
As Figure 1.1 shows, all materials can be classified as gases, simple liquids, or solids, with the understanding that most materials can be converted from one state to another through heating or cooling. If only materials that are structural solids at normal temperatures are examined, three major types of materials are encountered: metals, polymers, and ceramics. The polymer materials can be further divided into synthetic polymers and natural polymers. Most synthetic polymers are those that do not occur naturally and are represented by materials such as nylon, polyethylene, and polyester. Some synthetic polymers could be manufactured copies of naturally occurring materials (such as
Fused silica石英玻璃

Fused silica石英玻璃

Fused silica石英玻璃Fused silicaFused silicaFused Silica is the glassy form of quartz and is thus isotropic. It is tough and hard and has a very low expansion. Normal varieties contain water that gives strong absorption in the IR. Water-free varieties are available.Fused Silica includes three types: JGS1 (Ultraviolet Grade FusedSilica),JGS2 (Optical Grade Fused Quartz), and JGS3 (Full Spectrum Fused Silica).Today advances in raw material beneficiation permit transparent fusions from sand as well as from crystal. Consequently, if naturally occurring crystalline silica (sand or rock) is melted, the material is simply called Fused Quartz. If the silicon dioxide is synthetically derived, however, the material is referred to as synthetic Fused Silica.These materials are ultra pure, single component glasses (SiO2) with a unique combination of thermal, optical and mechanical properties, which make them the preferred materials for use in a variety of processes andapplications where other materials are not suitable. The very high purity (over 99.9%) ensures minimum contamination in process applications.Fused Quartz is less expensive vitreous silica formed by fusing naturally occurring quartz crystal or lower grade synthetic stock material, The UV useis limited to 250nm and this material is usually used for windows covering visible wavelengths.Fused Silica is vitreous silica formed by fusing high purity synthetic material. The UV use can be reached about 160nm.Ultraviolet Grade Fused Silica: JGS1 (China), equivalent to Suprasil 1 and 2 (Heraeus), Spectrosil A and B (Saint-Gobain) and Corning 7940 (Corning), Dynasil 1100 and 4100 (Dynasil).Optical Grade Fused Quartz: JGS2 (China), equivalent to Homosil 1, 2 & 3 (Heraeus), Dynasil 1000 & 4000 and 5000 & 6000 (Dynasil)Full Spectrum Fused Silica: JGS3 (China), equivalent to Suprasil 300 (Heraeus). Different Properties Parameter Value Maximum Size Transmission Range(Medium transmission ratio) OH- Content Fluorescence (ex 254nm) JGS10.17~2.10um (Tavg>90%) 1200 ppm Virtually Free JGS2 0.26~2.10um (Tavg>85%) 150 ppm Strong v-b JGS3 0.185~3.50um (Tavg>85%) 5 ppm Strong V-B Impurity Content Birefringence Constant Melting Method Applications 5 ppm 2-4 nm/cm Synthetic CVD 20-40 ppm 4-6 nm/cm Oxy-hydrogen melting 40-50 ppm 4-10 nm/cm Electrical melting Laser substrate: Window, Semiconductor and high IR & UV substrate lens, prism, mirror... temperature window------------------------Fused Silica, SiO2 Glass PropertiesFused silica is a noncrystalline (glass) form of silicon dioxide (quartz, sand). Typical of glasses, it lacks long range order in its atomic structure. It’s highly cross linked three dimensional structure gives rise to it’s high use temperature and low thermal expansion coefficient. .Key Fused Silica Properties Near zero thermal expansion Exceptionally good thermal shock resistance Very good chemical inertness Can be lapped and polished to fine finishes Low dielectric constant Low dielectric loss Good UV transparency . Typical Fused Silica Uses High temperature lamp envelopes Temperature insensitive optical component supports Lenses, mirrors in highly variable temperature regimes Microwave and millimeter wave components Aeronautical radar windows General Fused Silica Information High purity sand deposits provide the raw material for bulk refractory grade, which is electric arc melted at extremely high temperatures. Optical and general purpose fusedsilica rods and tubing are drawn from a melt made from high purity chemicals. Fiber optic purity is made by thermal decomposition of high purity gaseous silica containing chemicals. The glass may be clear or translucent, in which case it is often referred to as fused quartz. The glass has very high viscosity, and this property allows the glass to be formed, cooled and annealed without crystallizing. Fused silica glass is a very low thermal expansion material, and so is extremely thermal shock resistant. The material is also chemically inert up to moderate temperatures except to hydrofluoric acid, w hich dissolves silica. It will devitrify above about 1100°C in the presence of contaminants such as sodium, phosphorus and vanadium, with the formation of cristobalite crystals which destroy the properties of the glass.The dielectric properties are stable up through gigahertz frequencies. Download Fused Silica datasheet Fused Silica Engineering Properties*Fused Silica Mechanical Density Porosity Color Flexural Strength Elastic Modulus Shear Modulus Bulk Modulus Poisson’s Ratio Compressive Strength Hardness Fracture Toughness KIC Maximum Use Temperature (no load) Thermal Thermal Conductivity Coefficient Expansion Specific Heat Electrical Dielectric Strength Dielectric Constant Dissipation Factor Loss Tangent VolumeResistivity of Thermal Units of Measur e gm/cc (lb/ft3) % (%) ― MPa(lb/in2x103) GPa (lb/in2x106) GPa (lb/in2x106) GPa (lb/in2x106) ― MPa(lb/in2x103) Kg/mm2 MPa?m1/2 °C (°F) SI/Metric 2.2 0 clear ― 73 31 41 0.17 1108 600 ― 1100 (Imperial) (137.4) 0 ― ― (10.6) (4.5) (6) (0.17)(160.7) ― ― (2000) (9.6) (.31) (0.18) (750) (3.82) (0.00002) ― ― W/m?°K (BTU?in/ft2?hr?°F) 1.38 10�C6/°C (10�C6/°F) J/Kg?°K (Btu/lb?°F) ac-kv/mm (volts/mil) @ 1 MHz @ 1 MHz @ 1 MHz ohm?cm 0.55 740 30 3.820.00002 ― >1010 *All properties are room temperature values ex cept as noted. The data presented is typical of commercially available material and is offered for comparative purposes only. The information is not to beinterpreted as absolute material properties nor does it constitute a representation or warranty for which we assume legal liability. User shall determine suitability of the material for the intended use and assumes allrisk and liability whatsoever in connection therewith.感谢您的阅读，祝您生活愉快。

建材试验检测参数温湿度控制要求英文

建材试验检测参数温湿度控制要求英文

建材试验检测参数温湿度控制要求英文The temperature and humidity control requirements for building materials testing and inspection parameters are crucial to ensure accurate and reliable results. These requirements are essential for maintaining the integrity of the testing process and minimizing any potential variations or errors that may arise due to environmental factors. Several factors need to be considered when establishing temperature and humidity control requirements for building materials testing.Firstly, it is important to consider the specific characteristics of the building materials being tested. Different materials may have varying sensitivities to temperature and humidity, and their properties can be affected by changes in these conditions. For example, concrete may require specific temperature and humidity levels to ensure proper curing and strength development. Therefore, understanding the material's behavior and requirements is essential in determining the appropriatecontrol parameters.Secondly, the testing standards and guidelines provided by relevant industry organizations should be taken into account. These standards often provide specific recommendations for temperature and humidity control during testing to ensure consistency and comparability of results. Adhering to these standards helps to establish a common framework for testing and enables accurate evaluation and comparison of different building materials.Another perspective to consider is the influence of temperature and humidity on the testing equipment itself. Some testing equipment may be sensitive to environmental conditions, and variations in temperature and humidity can affect their performance and accuracy. Therefore, it is necessary to ensure that the testing equipment is properly calibrated and maintained to guarantee reliable and precise measurements. Additionally, controlling the temperature and humidity of the testing environment can help prolong the lifespan of the equipment and minimize the need for frequent recalibration or repairs.Furthermore, the safety of personnel involved in the testing process should not be overlooked. Extreme temperatures or high humidity levels can pose risks to the health and well-being of individuals working in the testing laboratory. Providing a comfortable and safe working environment is essential to ensure the accuracy and efficiency of the testing process. Therefore, temperature and humidity control requirements should also consider the well-being of the personnel involved.In addition to the technical aspects, economic considerations are also important when establishing temperature and humidity control requirements for building materials testing. Maintaining precise control over temperature and humidity levels can require specialized equipment and resources, which may come at a cost. Therefore, a balance between the desired control parameters and the available resources should be struck to ensure the feasibility and cost-effectiveness of the testing process.In conclusion, the temperature and humidity controlrequirements for building materials testing and inspection parameters are multifaceted. They encompass considerations such as the characteristics of the materials being tested, adherence to industry standards, equipment performance, personnel safety, and economic feasibility. By carefully evaluating and addressing these various perspectives, the control parameters can be established to facilitate accurate, reliable, and efficient testing of building materials.。

HHM800系列电流传感器产品说明书

HHM800系列电流传感器产品说明书

Q-43sensors. The HHM800 Series is lightweight and does not use magnetic cores like standard transformers.The transformation principle is based on an air core. It presents virtually no load to the system under test, has low phase shift and excellent frequency response and cannot be damaged by current overloads. The sensorassembly is waterproof and insulated for 1000 V working voltage. The HHM800 Series has an mV output proportional to the current measured for direct readings on DMM’s,loggers, oscilloscopes and power or harmonic meters. The length of the flexible sensor can be selected from 610 mm (24") to 1520 mm (60").HHM800 SeriesStarts at$ߜModels Ranging from 30 Amp RMS to 30,000 Amp RMSߜ Accuracy 1% of Reading ߜ True rms Measurement When Connected to a True RMS Instrument ߜNo Core Saturationor Damage if Overloaded ߜOverrange LED for Measurement Circuitry ߜ1000 V IEC 1010 Cat III, CE Mark ߜWaterproof Sensor ߜ9 V Battery for Typical 150 Hour Continuous Operationߜ Custom Pre-Shaping of Sensor Before Use (No Drooping)ߜ Very High Frequency ResponseߜLow Phase Shift for Power Measurements ߜ Insensitive to DC,Measures Only AC Component on DC+AC Signalsߜ Excellent Linearity ߜ Lightweight DesignFlexible AC Current ProbesCommon SpecificationsAccuracy:1% of readingFrequency Range:10 to 20,000 HzWorking Voltage:1000 V IEC-1010 Cat.III Safety Standards:Designed to IEC 1010 and CE mark CE Markings:1997Operating Temperature and % RH: -20 to 55°C (sensor to 90°C), 0 to 90% RH (@ 50°C)Minimum Bend Radius:19 mm (0.75") Water and Dustproofing: Sensor IP65(NEMA 4X), Module IP40Battery and Battery Life:9 V alkaline(included), approx 150 hr of continuous use Good Battery Indication: Green LEDElectronic Overload Indication:Red LED Output: 3⁄4" spaced banana jacks, optional banana plug to BNC adaptor available, 2 m (6.5') lead from sensor to moduleThe HHM800 Series flexible ac current probes are composed of a flexible sensor and an electronic module. The flexible sensor permits measurements on conductors where standard clamp-on probes cannot be used.In particular, it can be installed in tight spaces, around cable bundles,around wide or large bus bars or even wrapped around irregularly shaped objects. Probe design enables the user to pre-shape the sensor before inserting it between or around conductors. This feature facilitates positioning the sensoraround the conductor, enhances user safety and alleviates the drooping effect associated with other flexibleHHM802, $299, shown smaller than actual size.Q-44Electrical SpecificationsStandard length is 610 mm (24"). Please consult sales foravailability and pricing for 910, 1220, and 1520 mm (36, 48, and 60") models. Comes with 9 V battery and operator’s manual.Ordering Example:HHM805, flexible current probe andHHM70-CONN1, banana plug to BNC adaptor, $319 + 38 = $357.CANADA www.omega.ca Laval(Quebec) 1-800-TC-OMEGA UNITED KINGDOM www. Manchester, England0800-488-488GERMANY www.omega.deDeckenpfronn, Germany************FRANCE www.omega.frGuyancourt, France088-466-342BENELUX www.omega.nl Amstelveen, NL 0800-099-33-44UNITED STATES 1-800-TC-OMEGA Stamford, CT.CZECH REPUBLIC www.omegaeng.cz Karviná, Czech Republic596-311-899TemperatureCalibrators, Connectors, General Test and MeasurementInstruments, Glass Bulb Thermometers, Handheld Instruments for Temperature Measurement, Ice Point References,Indicating Labels, Crayons, Cements and Lacquers, Infrared Temperature Measurement Instruments, Recorders Relative Humidity Measurement Instruments, RTD Probes, Elements and Assemblies, Temperature & Process Meters, Timers and Counters, Temperature and Process Controllers and Power Switching Devices, Thermistor Elements, Probes andAssemblies,Thermocouples Thermowells and Head and Well Assemblies, Transmitters, WirePressure, Strain and ForceDisplacement Transducers, Dynamic Measurement Force Sensors, Instrumentation for Pressure and Strain Measurements, Load Cells, Pressure Gauges, PressureReference Section, Pressure Switches, Pressure Transducers, Proximity Transducers, Regulators,Strain Gages, Torque Transducers, ValvespH and ConductivityConductivity Instrumentation, Dissolved OxygenInstrumentation, Environmental Instrumentation, pH Electrodes and Instruments, Water and Soil Analysis InstrumentationHeatersBand Heaters, Cartridge Heaters, Circulation Heaters, Comfort Heaters, Controllers, Meters and SwitchingDevices, Flexible Heaters, General Test and Measurement Instruments, Heater Hook-up Wire, Heating Cable Systems, Immersion Heaters, Process Air and Duct, Heaters, Radiant Heaters, Strip Heaters, Tubular HeatersFlow and LevelAir Velocity Indicators, Doppler Flowmeters, LevelMeasurement, Magnetic Flowmeters, Mass Flowmeters,Pitot Tubes, Pumps, Rotameters, Turbine and Paddle Wheel Flowmeters, Ultrasonic Flowmeters, Valves, Variable Area Flowmeters, Vortex Shedding FlowmetersData AcquisitionAuto-Dialers and Alarm Monitoring Systems, Communication Products and Converters, Data Acquisition and Analysis Software, Data LoggersPlug-in Cards, Signal Conditioners, USB, RS232, RS485 and Parallel Port Data Acquisition Systems, Wireless Transmitters and Receivers。