The Engineer's Guide to Temperature Sensing
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The NTC Thermistors This Is a Negative Temperature Coeffi Cient Resistor Whose Resistance Changes As Ambient Temperature Changes
NTC Thermistors The NTC Thermistors This is a Negative Temperature Coeffi cient Resistor whose resistance changes as ambient temperature changes. Therm- istor comprises 2 or 4 kinds of metal oxides of iron, nickel, cobalt, manganese and copper, being shaped and sintered at high temperature (1200 to 1500 °C) ■ Features ■ Recommended Applications ● Temperature Coeffi cient of Resistance is negative and ● For temperature measurement or temperature detection : extremely large thermometer, temperature controller ● Various kinds of types especially smaller ones are ● For temperature compensation : transistor circuit, available. measuring instruments ● Resistance values are available from 22 Ω to 470 kΩ ■ Physical Characteristics of NTC Thermistors Thermistor is a resistor sensitive to temperature utilizing Fig. 1 the large temperature-coefficient of metal oxide semi- conductor. And its temperature dependency of resistance 1000 value is indicated by the following equation: 1 1 100 R=R0 exp B .................................... (1) ( )[ ( T T 0 )[ ] 10 T0: Standard Temperature 298.15 K(25 °C) 25 0 0 R: Resistance at T K /R 1 T B: Thermistor Constant (K) R B=1000 So called Temperature Coefficient (a) is generally 2000 3000 indicated as follows: 0.1 4000 B 5000 a= .................................................................... (2) T2 0.01 6000 But a is not adequate for use as a constant, because a 0.001 change by temperature is considerably large, so B Value –40 –20 0 20 40 60 80 100 120 140 is used as a coeffi cient of thermistor. T (˚C) ■ Major Characteristics of NTC Thermistors The relation between resistance and temperature of a Fig. 2 thermistor is linear as shown in Fig. -
NTC Thermistors Circuit Protection Components
Product catalog Product NTC thermistors Circuit protection components Cat. No. 129L INDEX 1.Application examples ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 3 2.What are "NTC thermistors"? ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 4 3.Basic specifications ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 4 4.How to choose the right thermistor ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 5 5.How to choose the right power thermistor ‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥‥ 5 Type desription SEMITEC series name Temperature range ■ Micro thin film thermistor FT thermistor (- 40 ℃ to 250 ℃ ) ‥‥‥‥‥‥‥ 6 - 7 ■ Micro thin film type sensor probe Fµ thermistor (- 10 ℃ to 70 ℃ ) ‥‥‥‥‥‥‥ 8 ■ Thin film thermistor JT thermistor (- 40 ℃ to 100 ℃ ) ‥‥‥‥‥‥‥ 9 ■ Very high accuracy thermistor AP thermistor (- 60 ℃ to 150 ℃ ) ‥‥‥‥‥‥‥ 10 - 11 ■ High accuracy thermistor AT thermistor (- 50 ℃ to 110 ℃ ) ‥‥‥‥‥‥‥ 12 - 13 ■ High sensitivity thermistor ET thermistor (- 50 ℃ to 125 ℃ ) ‥‥‥‥‥‥‥ 14 - 15 ■ SMD type thermistor KT thermistor (- 40 ℃ to 125 ℃ ) ‥‥‥‥‥‥‥ 16 - 17 ■ High temperature thermistor NT thermistor (- 50 ℃ to 300 ℃ ) ‥‥‥‥‥‥‥ 18 CT thermistor (- 50 ℃ to 250 ℃ ) ‥‥‥‥‥‥‥ 19 ■ Non-contact (IR) temperature sensor NC sensor (- 10 ℃ to 150 ℃ ) ‥‥‥‥‥‥‥ 20 Thermopile (- 50 ℃ to 200 ℃ ) ‥‥‥‥‥‥‥ 21 ■ Current regulating diode CRD (- 40 ℃ to 150 ℃ ) ‥‥‥‥‥‥‥ 22 - 23 ■ Voltage regulating diode VRD (- 40 ℃ to 150 ℃ ) ‥‥‥‥‥‥‥ 24 - 25 ■ Inrush current limiter Power thermistor (- 50 ℃ to 200 ℃ ) ‥‥‥‥‥‥‥ 26 - 27 High accuracy Fμ Thermistor AP Thermistor FT Thermistor ET Thermistor JT Thermistor AT Thermistor SMD type KT Thermistor NT Thermistor -
Thermometrics NTC Diode Thermistors
NTC Diode Thermometrics Thermistors A range of NTC chip thermistors in DO-35 style • Available on axial bandolier to IEC-286-1/ glass package (diode outline) with axial solder- EIA-468A and packet taped to EIA RS-481 for coated copper-clad steel wires. MELF. • Designed for accurate temperature • Also available loose-packed with axial, radial measurement, control and compensation and SMD wire forms • Tight tolerances on resistance and B value • Suitable for automotive, telecom (battery packs), HVAC and white goods applications • Operation up to 482°F (250°C) with excellent stability • Temperature sensing for household appliances such as rice cookers, electronic • Glass body provides hermetic seal and ranges, ovens, etc. voltage insulation and excellent stability • Temperature sensing for industrial products • Designed for cost effective solid state sensor such as pharmaceuticals, chemicals, food, etc.components. • Lead-wires metallurgically bonded to thermistor element for improved reliability (Type GE only) • Resistant to corrosive atmospheres and harsh environments Amphenol Advanced Sensors Type DK 0.08 in (2 mm) 0.02 in (0.5 mm) Specifications DK-N maximum nominal Chip thermistor in DO-35 glass package 1.06 in (27 mm) 0.2 in (4.2 mm) minimum maximum Options DK-H • Other resistance values within the ranges shown; e.g. code DKA302*2 for 3000 Ω 0.08 in (2 0.16 in (4 mm) mm) maximum 0.1 in (2.8 mm) Inside radius ±2% at 77°F (25°C) nominal Ø 0.02 in (0.5 mm) nominal 0.05 in (1.2 • Reference temperatures in the range 0°F mm) nominal to 302°F -
Application Note
VISHAY BCCOMPONENTS www.vishay.com Resistive Products Application Note NTC Thermistors APPLICATIONS AUTOMOTIVE APPLICATIONS INDUSTRIAL, TELECOMMUNICATIONS, CONSUMER NTC temperature sensors are widely used in motor vehicles. In switching, measuring and detection systems For example: • Process control • Inlet air-temperature control • Heating and ventilation • Transmission oil temperature control • Air conditioning • Engine temperature control • Fire alarms • Airco systems • Temperature protection in battery management / charging • Airbag electronic systems systems • Temperature detection of laser diode in CD players for • LCD contrast control in flat-panel displays, mobile phones cars and camcorders • Frost sensors • Temperature compensation of quartz oscillator frequency •ABS in, for example, mobile phones • BMS / charge plugs protection • Ink-jet printer head temperature detection • Video and audio equipment DOMESTIC APPLIANCES • LED control circuits NTC temperature sensors are in virtually all equipment in the home where temperature plays a role. This includes: • Fridges and freezers • Cookers and deep-fat fryers • Washing machines and dish washers • Central-heating systems • Air conditioning SELECTION CHART TOL. LEAD OPERATING B RESP. MAX. ON R (± %) DOCUMENT PRODUCT RANGE TEMP. RANGE TOL. TIME Ø OR Ø L NUMBER (°C) (± %) (s) (mm) ON T (± °C) (mm) (mm) Accuracy line APPLICATION NOTE NTCLE203E3 -40 to +125 (1 , 2, 3, 5) % 0.5 to 2.5 1.7 3.4 0.4 38 min. 29048 NTCLE100E3 -40 to +125 (2, 3, 5) % 0.5 to 3.0 1.2 3.8 0.6 17 min. 29049 two-point NTCLE101E3...SB0 -40 to +125 0.5 °C 1.2 3.3 0.6 17 min. 29046 sensors two-point NTCLE203E3...SB0 -55 to +150 0.5 °C 1.7 4.2 0.5 41 29118 sensors SMD versions NTCS0603E3 -40 to +150 (1, 2, 3, 5) % 1 - - - - 29056 NTCS0402E3 -40 to +150 (1, 2, 3, 5) % 3 - - - - 29003 NTCS0805E3 -40 to +150 (1, 2, 3, 5) % 1 - - - - 29044 NTCS….E3…SMT -40 to +125 1 % 1 - - - - 29151 Revision: 27-Jan-2021 1 Document Number: 29053 For technical questions, contact: [email protected] THIS DOCUMENT IS SUBJECT TO CHANGE WITHOUT NOTICE. -
1 Light-Emitting Diode
1 Light-emitting diode parameter n is called the ideality factor and usually 1 < n < 2. The parameter VG0 is called the nominal Light Emitting Diodes (LEDs) are the most efficient bandgap voltage of the semiconductor material. 0 light sources. During recent years, the cheap, powerful The voltage across a physical diode V = V + IdRs and reliable LED light bulbs appeared on the market. has also contribution from a parasitic series resistance This is making a true revolution worldwide, as other Rs which is of the order of 1 Ω. Hint: estimate the electrical lighting tools (e.g. incandescent, halogen and magnitudes in the expression above and simplify your fluorescent) in homes and offices are being replaced with calculations accordingly! LED lighting. In this experiment, we will analyse thermal and elec- 1. Measure and plot the voltage–temperature graph of trical properties of the light emitting diodes. the LED at a constant current (your current should You do not need to estimate any uncertainties, but be small enough so that the voltage drop on Rs can the accuracy of your methods and results is important be neglected). and will be graded. Always draw the measurement setup Find VG0. you use! When appropriate, use graphs for determining required quantities. Find the parameters n and A by making additional measurements and a suitable plot. Equipment: 2 identical circuit boards with a LED, res- istor and a temperature sensor on them; 2 transparent At larger currents, the series resistance Rs becomes bottles, 2 airtight caps, 2 tubes, water, syringe, 3 multi- noticeable. Measure this Rs. -
Occupational Exposure to Heat and Hot Environments
Criteria for a Recommended Standard Occupational Exposure to Heat and Hot Environments DEPARTMENT OF HEALTH AND HUMAN SERVICES Centers for Disease Control and Prevention National Institute for Occupational Safety and Health Cover photo by Thinkstock© Criteria for a Recommended Standard Occupational Exposure to Heat and Hot Environments Revised Criteria 2016 Brenda Jacklitsch, MS; W. Jon Williams, PhD; Kristin Musolin, DO, MS; Aitor Coca, PhD; Jung-Hyun Kim, PhD; Nina Turner, PhD DEPARTMENT OF HEALTH AND HUMAN SERVICES Centers for Disease Control and Prevention National Institute for Occupational Safety and Health This document is in the public domain and may be freely copied or reprinted. Disclaimer Mention of any company or product does not constitute endorsement by the National Institute for Occupational Safety and Health (NIOSH). In addition, citations of websites external to NIOSH do not constitute NIOSH endorsement of the sponsoring organizations or their programs or products. Furthermore, NIOSH is not responsible for the content of these websites. Ordering Information This document is in the public domain and may be freely copied or reprinted. To receive NIOSH documents or other information about occupational safety and health topics, contact NIOSH at Telephone: 1-800-CDC-INFO (1-800-232-4636) TTY: 1-888-232-6348 E-mail: [email protected] or visit the NIOSH website at www.cdc.gov/niosh. For a monthly update on news at NIOSH, subscribe to NIOSH eNews by visiting www.cdc.gov/ niosh/eNews. Suggested Citation NIOSH [2016]. NIOSH criteria for a recommended standard: occupational exposure to heat and hot environments. By Jacklitsch B, Williams WJ, Musolin K, Coca A, Kim J-H, Turner N. -
A Thermistor Is a Type of Resistor Used to Measure Temperature Changes
Name of student:…………………………………….. 7 PHYSICAL CHARACTERISTICS OF THERMISTOR Task: Determine physical characteristics of a thermistor (constants A and B) from five temperature and resistance measurement. Calculate the resistance of the termistor and the temperature coefficient % at 0, 25 oC using the Equations [3] and [5] and the obtained values A and B. The word thermistor is a combination of words “thermal” and “resistor”. A thermistor is a temperature-sensing element composed of sintered semiconductor material which exhibits a large change in resistance proportional to a small change in temperature. Thermistors can be classified into two types: If the resistance increases with increasing temperature, the device is called a positive temperature coefficient (PTC) thermistor, posistor. If the resistance decreases with increasing temperature, the device is called a negative temperature coefficient (NTC) thermistor. PTC thermistors can be used as heating elements in small temperature-controlled ovens. NTC thermistors are used as resistance thermometers in low-temperature measurements of the order of 10 K. NTC thermistors can be used also as inrush- current limiting devices in power supply circuits. They present a higher resistance initially which prevents large currents from flowing at turn-on, and then heat up and become much lower resistance to allow higher current flow during normal operation. These thermistors are usually much larger than measuring type thermistors, and are purpose designed for this application. Thermistors are also commonly -
Thermal Derating of Leds
Thermal derating of LEDs In the last few years, the high-brightness LEDs have developed enormously from a niche existence as a high-priced designer spotlight to a useful general purpose illumination source with efficiencies of up to 160 Lumens/Watt and lifetimes measured in decades. As high power LEDs have become more popular as an alternative to wasteful incandescent bulbs or toxic CFL lamps , the economies of scale have caused the price of LEDs to fall to a level where they can now compete in mass markets rather than just the cutting edge applications. However, the introduction of high power LED Technology has pushed the issue of thermal management back to the forefront of lighting design. Like all semiconductors, LEDs must not overheat otherwise their celebrated long lifetimes will be adversely affected. Although the efficiency of a standard high power LED is around six times better than a standard incandescent light bulb and around twice as good as a fluorescent, a significant amount of the electrical energy flowing through the device is still converted into heat. Therefore, it is essential that thermal management and the consideration of the effects of high environmental temperatures are addressed right at the start of the design phase. Figure 1a: Effect of ambient temperature on lifetime Figure 1b: Typical LED temperature derating curve Figure 1a shows how the lifetime of power LEDs drops rapidly once the high ambient temperature causes the internal junction temperature to exceed 130°C. The maximum ambient operating temperature is dependent on the internal thermal design of the LED, its efficiency and its power dissipation, so it varies from manufacturer to manufacturer. -
Dictionary: Know Your Resistors
TN-009 Tech Note Dictionary: Know Your Resistors Adhesion: The ability of dissimilar metals or particles to cling together as a joint is referred to as adhesion. Adhesion in thick film is created by either a chemical (oxide bonded) or mechanical (Frit) bonds. Peel test can be used to measure adhesion between lead and substrate and dielectric. Alpha coefficient: In a thermally sensitive resistor or Thermistor applications, the alpha (α) coefficient is a material characteristics which defines the percentage resistance change per degree centigrade. It is also known as the temperature coefficient and it’s calculated by the following relationship; 1 dR α = /RT x /dT Where RT is the resistance of the component at the relevant temperature in (°C), dR/dT is the gradient of the R vs. T curve at that temperature point and alpha is expressed in (%/°C) Annealing: Annealing is a heat process whereby a material (metal or glass) is heated to a specific temperature (annealed point) and then allowed to cool slowly in order to maintain ductility and prevent crack and internal stress. Aspect Ratio (AR): The ratio of resistor length to resistor width is the aspect ratio. It’s also known as the number of squares. Amplitude Balance: The maximum deviation or difference in amplitude between the output ports of a power divider across the operating frequency range. It’s measured in dB AQL (Acceptable Quality Limit): This is a statistical measurement of the maximum number of defective goods considered acceptable in a particular sample size or lot. Attenuation: The loss of signal (Power or Amplitude level) in transmission through the use of attenuators or a filter; It’s measured in decibels (dB). -
Thermal Management of Microelectronic Equipment Heat Transfer Theory, Analysis Methods, and Design Practices
THERMAL MANAGEMENT OF MICROELECTRONIC EQUIPMENT HEAT TRANSFER THEORY, ANALYSIS METHODS, AND DESIGN PRACTICES Downloaded From: http://ebooks.asmedigitalcollection.asme.org/ on 01/05/2016 Terms of Use: http://www.asme.org/about-asme/terms-of-use ASME Press Book Series on Electronic Packaging Dereje Agonafer, Editor-in-Chief Associate Technical Editors Administrative Editors Cristina Amon, Carnegie Mellon University Damena Agonafer A. Haji-Sheikh, University of Texas, Arlington University of Texas, Arlington Yung-Cheng Lee, University of Colorado, Boulder Wataru Nakayama, ThermTech International Senayet Agonafer Shlomo Novotny, Sun Microsystems Princeton University Al Ortega, University of Arizona, Tucson Donald Price, Raytheon Electronic Systems Viswam Puligandla, Nokia Koneru Ramakrishna, Motorola, Inc. Gamal Refai-Ahmed, Ceyba Inc. Bahgat Sammakia, SUNY, Binghamton Roger Schmidt, IBM Masaki Shiratori, Yokohama National University Suresh Sitaraman, Georgia Institute of Technology Ephraim Suhir, Iolon, Inc. About the Series Electronic packaging is experiencing unprecedented growth, as it is the key enabling technology for applications ranging from computers and telecommuni- cations, to automobiles and consumer products. Although technology improve- ments are still possible, these solutions are becoming quite expensive. In addition, technology enhancements seem to be reaching physics-based limits. Therefore, packaging can present an opportunity for performance improvements without the need for new CMOS technology. At InterPACK 1999, the flagship con- ference of the Electronic and Photonic Packaging Division, the electronic pack- aging business worldwide was estimated to be over $100 billion per year. The rapidly changing technology necessitates current and up-to-date technical knowl- edge on the subject for both practicing engineers and academic researchers. It was with this background that this book series was initiated. -
Packaging Design & Manufacture of High Temperature Electronics
Packaging Design & Manufacture of High Temperature Electronics Module for 225ºC Applications utilizing Hybrid Microelectronics Technology Jacob M. Li Vectron International 267 Lowell Road Hudson, NH, 03051 Tel 603-598-0070, [email protected] Abstract Many downhole instrumentation tools manufacture today utilizing organic material packaging technology for producing electronic modules. Such approach with organic PCB, standard packaged discrete semiconductor and SMT-type passive components has limited the device operating temperature range in 177ºC area. An alternative packaging approach is to utilize Hybrid Microelectronics Technology to increase the operating temperature limit up to 225ºC in production environment. Besides performance improvements on upper operating temperature limit, thermal cycling, high frequency shock and vibration, based on our customer’s reliability testing data, hermetically sealed high-temperature Hybrid module’s survivability can exceed over 7000 hours of MTTF at 225ºC high temperature storage condition along with other environmental matrix testing. Moreover, comparing with high-temperature SMT and Thru-hole Technologies, Hybrid Microcircuit increases packaging density and provides valuable real estate saving. Vectron International has successfully utilized Hybrid Technology to manufacture thousands of hi- temperature electronic module for 200ºC to 225ºC applications. This paper describes the packaging design of a 225ºC hi-temp electronic module for down-hole application using such technology. This paper will also touch bases on material selection, fabrication technique and some reliability data of this high- temperature Hybrid module. Key Words: High Temperature Electronics, Hermetic Seal, Thick-Film Introduction industry, but it could develop tremendously if the automotive market opens up. Aerospace is Extreme environment applications require another area that show promise for the near electronic system survived beyond the term [1]. -
Arctic Sun® 2000 Operator’S Manual Contents
Arctic Sun® 2000 Operator’s Manual contents Preface . iv Customer Information and Technical Support . v Section One 1 .1 Introduction . 6 1 .2 Symbols and Standards . 7 1 .3 Environmental Conditions . 9 1 .4 Indications for Use . 9 1 .5 Contraindications for Use . 10 1 .6 Warnings . 10 1 .7 Cautions . 11 Section Two 2 .1 System Description . 16 2 .2 Model 2000 Components . 18 2 .3 Remote Display and Controls . 20 2 .4 Fluid Delivery Line . 24 2 .5 Patient Temperature Cables and Probes . 24 2 .6 Temperature Out . 25 2 .7 ArcticGel Pads . 26 Section Three 3 .1 Initial Setup . 28 3 .2 Filling the Control Module . 28 3 .3 Location of the Patient . 30 3 .4 Draining the Control Module . 31 3 .5 Cleaning and Maintenance . 31 ii Arctic Sun 2000 Operator’s Manual 3 .6 Service and Calibration . 34 3 .7 Warranty . 35 Section Four 4 .1 Beginning a Procedure . 36 4 .2 Setting Custom Parameters . 36 4 .3 Collecting Data . 40 4 .4 Pre-warming or Pre-cooling the Model 2000 . 41 4 .5 Placing the ArcticGel Pads . 42 4 .6 Connecting the Pads to the Fluid Delivery Lines . 47 4 .7 Pad Weights . 48 4 .8 Treating a Patient Using Automatic Mode . 49 4 .9 Treating a Patient Using Manual Mode . 53 4 .10 Water Flow Rate . 55 4 .11 Interrupting Treatment for Patient Transport . 56 4 .12 Ending a Procedure . 56 Section Five 5 .1 Alarms . 58 5 .2 Alerts . 60 5 .2 Troubleshooting the Arctic Sun System . 60 Appendices A . Installation Procedure .