NTC thermistors for temperature measurement Probe assemblies Series/Type: B57276K Date: February 2009 © EPCOS AG 2009. Reproduction, publication and dissemination of this publication, enclosures hereto and the information contained therein without EPCOS' prior express consent is prohibited. Temperature measurement B57276K Probe assemblies K276 Applications Washing machines Dish washers Tumble-dryers Water boilers Features Suitable for use in corrosive environments Compact stainless steel case RAST 2.5 or RAST 5 connector Cost-effective ready-to-use sensor UL approval (E69802) VDE approval (DIN EN 60539-1: 2002) Options Alternative resistance ratings, rated temperatures and resistance tolerances available on request. RAST 5 plug terminals or RAST 2.5 connector with bar available on request. Type Z276 and Z278 with different geometry and faster response time available on request. Delivery mode Bulk Dimensional drawings Dimensions R60 Ω A max. Plug terminal mm mm RAST 2.5 connector 1204 ∅ 14.5 3243 ∅ 12.4 RAST 5 connector 1082 ∅ 14.5 3243 ∅ 12.4 Approx. weight 9 g Approx. weight 9 g Please read Cautions and warnings and Important notes at the end of this document. Page 2 of 11 6.3 x 0.8 4.8 x 0.8 Temperature measurement B57276K Probe assemblies K276 General technical data Climatic category Max. power Resistance tolerance Dissipation factor Thermal time constant Heat capacity Insulation resistance Test voltage (IEC 60068-1) (at 25 °C) (in water) (in water) (V = 100 V DC) (t = 1 s) P25 ∆RR/RR δth τa Cth Rins Vtest 10/100/56 500 ±2 approx. 20 approx. 20 approx. 500 > 1000 3750 mW % mW/K s mJ/K MΩ V AC Electrical specification and ordering codes TR °C RR Ω RAST 2.5 connector 60 1204 60 3243 RAST 5 connector 63 1082 60 3243 R25 Ω No. of R/T B25/100 characteristic K 4829 11981 2003 2901 3980 ±1% 3760 ±1.5% B57276K0482A007 B57276K0123A028 4829 11981 2003 2901 3980 ±1.5% 3760 ±1.5% B57276K0482A009 B57276K0123A024 Please read Cautions and warnings and Important notes at the end of this document. Page 3 of 11 Ordering code Temperature measurement B57276K Probe assemblies K276 Reliability data Test Standard Storage in dry heat IEC 60068-2-2 Storage in damp heat, steady state Rapid temperature cycling Endurance Long-term stability (empirical value) Robustness of terminations Test conditions Storage at upper category temperature T: 100 °C t: 1000 h IEC Temperature of air: 40 °C 60068-2-78 Relative humidity of air: 93% Duration: 56 days IEC Lower test temperature: 10 °C 60068-2-14 Upper test temperature: 100 °C Number of cycles: 10 Pmax: 500 mW t: 1000 h Temperature: 100 °C t: 10000 h DIN Pull-out force 46 249 (both connectors together) F = 50 N Please read Cautions and warnings and Important notes at the end of this document. Page 4 of 11 ∆R25/R25 (typical) < 2% Remarks < 1% No visible damage < 1% No visible damage < 2% No visible damage No visible damage No visible damage < 3% No visible damage Temperature measurement B57276K Probe assemblies K276 R/T characteristics R/T No. T (°C) 2003 2901 B25/100 = 3980 K B25/100 = 3760 K RT/R25 α (%/K) RT/R25 α (%/K) 55.0 50.0 45.0 40.0 35.0 97.578 67.65 47.538 33.831 24.359 7.5 7.2 7.0 6.7 6.5 63.969 46.179 33.738 24.927 18.611 6.7 6.4 6.2 6.0 5.8 30.0 25.0 20.0 15.0 10.0 17.753 13.067 9.7228 7.3006 5.5361 6.3 6.0 5.8 5.6 5.5 14.033 10.679 8.198 6.3123 4.9014 5.6 5.4 5.3 5.2 5.1 5.0 0.0 5.0 10.0 15.0 4.2332 3.266 2.5392 1.9902 1.5709 5.3 5.1 5.0 4.8 4.7 3.821 3.0027 2.3801 1.9 1.5257 4.9 4.7 4.6 4.5 4.3 20.0 25.0 30.0 35.0 40.0 1.2492 1.0000 0.80575 0.65326 0.5329 4.5 4.4 4.3 4.1 4.0 1.233 1.0000 0.81679 0.67166 0.55527 4.3 4.1 4.0 3.9 3.8 45.0 50.0 55.0 60.0 65.0 0.43715 0.36064 0.29908 0.24932 0.20886 3.9 3.8 3.7 3.6 3.5 0.46095 0.38459 0.32184 0.27068 0.22907 3.8 3.7 3.6 3.5 3.3 70.0 75.0 80.0 85.0 90.0 0.17578 0.14863 0.12621 0.10763 0.092159 3.4 3.3 3.2 3.1 3.1 0.19468 0.16607 0.14221 0.12218 0.10533 3.2 3.1 3.1 3.0 2.9 95.0 100.0 105.0 110.0 115.0 0.079225 0.068356 0.059247 0.051531 0.044921 3.0 2.9 2.8 2.8 2.7 0.09123 0.079284 0.069062 0.06034 0.052886 2.8 2.8 2.7 2.7 2.6 120.0 125.0 130.0 135.0 140.0 0.039282 0.034387 0.030186 0.02665 0.023594 2.7 2.6 2.5 2.5 2.4 0.046482 0.040985 0.036233 0.032101 0.02851 2.5 2.5 2.5 2.4 2.4 145.0 150.0 155.0 0.020931 0.018616 0.016612 2.4 2.3 2.3 0.025373 0.022633 0.020231 2.3 2.3 2.3 Please read Cautions and warnings and Important notes at the end of this document. Page 5 of 11 Temperature measurement B57276K Probe assemblies Please read Cautions and warnings and Important notes at the end of this document. K276 Page 6 of 11 Temperature measurement B57276K Probe assemblies K276 Cautions and warnings General See "Important notes" at the end of this document. Storage Store thermistors only in original packaging. Do not open the package prior to storage. Storage conditions in original packaging: storage temperature 25 °C ... +45 °C, relative humidity ≤75% annual mean, <95% maximum 30 days per annum, dew precipitation is inadmissible. Do not store thermistors where they are exposed to heat or direct sunlight. Otherwise, the packing material may be deformed or components may stick together, causing problems during mounting. Avoid contamination of thermistor surface during storage, handling and processing. Avoid storage of thermistors in harmful environments like corrosive gases (SOx, Cl etc). Use the components as soon as possible after opening the factory seals, i.e. the polyvinyl-sealed packages. Solder thermistors within the time specified after shipment from EPCOS. For leaded components this is 24 months, for SMDs 12 months. Handling NTC thermistors must not be dropped. Chip-offs or any other damage must not be caused during handling of NTCs. Do not touch components with bare hands. Gloves are recommended. Avoid contamination of thermistor surface during handling. Bending / twisting leads A lead (wire) may be bent at a minimum distance of twice the wire’s diameter plus 4 mm from the component head or housing. When bending ensure the wire is mechanically relieved at the component head or housing. The bending radius should be at least 0.75 mm. Twisting (torsion) by 180° of a lead bent by 90° is permissible at 6 mm from the bottom of the thermistor body. Soldering Use resin-type flux or non-activated flux. Insufficient preheating may cause ceramic cracks. Rapid cooling by dipping in solvent is not recommended. Complete removal of flux is recommended. Please read Cautions and warnings and Important notes at the end of this document. Page 7 of 11 Temperature measurement B57276K Probe assemblies K276 Mounting Ensure that no thermo-mechanical stress occurs due to production processes (curing or overmolding processes) when thermistors are sealed, potted or overmolded or during their subsequent operation. The maximum temperature of the thermistor must not be exceeded. Ensure that the materials used (sealing/potting compound and plastic material) are chemically neutral. Electrodes/contacts must not be scratched or damaged before/during/after the mounting process. Contacts and housing used for assembly with the thermistor must be clean before mounting. Ensure that adjacent materials are designed for operation at temperatures comparable to the surface temperature of the thermistor. Be sure that surrounding parts and materials can withstand the temperature. Avoid contamination of the thermistor surface during processing. The connections of sensors (e.g. cable end, wire end, plug terminal) may only be exposed to an environment with normal atmospheric conditions. Tensile forces on cables or leads must be avoided during mounting and operation. Bending or twisting of cables or leads directly on the thermistor body is not permissible. Avoid using chemical substances as mounting aids. It must be ensured that no water or other liquids enter the NTC thermistors (e.g. through plug terminals). In particular, water based substances (e.g. soap suds) must not be used as mounting aids for sensors. Operation Use thermistors only within the specified operating temperature range. Use thermistors only within the specified power range. Environmental conditions must not harm the thermistors. Only use the thermistors under normal atmospheric conditions or within the specified conditions. Contact of NTC thermistors with any liquids and solvents should be prevented. It must be ensured that no water enters the NTC thermistors (e.g. through plug terminals). For measurement purposes (checking the specified resistance vs. temperature), the component must not be immersed in water but in suitable liquids (e.g. Galden). Avoid dewing and condensation unless thermistor is specified for these conditions. Bending or twisting of cables and/or wires is not permissible during operation of the sensor in the application. Be sure to provide an appropriate fail-safe function to prevent secondary product damage caused by malfunction. This listing does not claim to be complete, but merely reflects the experience of EPCOS AG. Please read Cautions and warnings and Important notes at the end of this document. Page 8 of 11 Temperature measurement B57276K Probe assemblies K276 Symbols and terms Symbol English German A AWG Area American Wire Gauge Fläche Amerikanische Norm für Drahtquerschnitte B B25/100 B value B value determined by resistance measurement at 25 °C and 100 °C B-Wert B-Wert, ermittelt durch Widerstandsmessungen bei 25 °C und 100 °C Cth Heat capacitance Wärmekapazität I Current Strom N Number (integer) Anzahl (ganzzahliger Wert) P25 Pdiss Pel Pmax Maximum power at 25 °C Power dissipation Electrical power Maximum power within stated temperature range Maximale Leistung bei 25 °C Verlustleistung Elektrische Leistung Maximale Leistung im angegebenenTemperaturbereich ∆RB/RB Resistance tolerance caused by spread of B value Insulation resistance Parallel resistance Rated resistance Resistance tolerance Series resistance Resistance at temperature T (e.g. R25 = resistance at 25 °C) Widerstandstoleranz, die durch die Streuung des B-Wertes verursacht wird Isolationswiderstand Parallelwiderstand Nennwiderstand Widerstandstoleranz Serienwiderstand Widerstand bei Temperatur T (z.B. R25 = Widerstand bei 25 °C) T ∆T t TA Tmax Temperature Temperature tolerance Time Ambient temperature Upper category temperature Tmin Lower category temperature Temperatur Temperaturtoleranz Zeit Umgebungstemperatur Obere Grenztemperatur (Kategorietemperatur) Untere Grenztemperatur (Kategorietemperatur) Top TR Tsurf Operating temperature Rated temperature Surface temperature Betriebstemperatur Nenntemperatur Oberflächentemperatur V Vins Vop Vtest Voltage Insulation test voltage Operating voltage Test voltage Spannung Isolationsprüfspannung Betriebsspannung Prüfspannung Rins RP RR ∆RR/RR RS RT Please read Cautions and warnings and Important notes at the end of this document. Page 9 of 11 Temperature measurement B57276K Probe assemblies K276 Symbol English German α Temperature coefficient Temperaturkoeffizient ∆ Tolerance, change Toleranz, Änderung δth Dissipation factor Wärmeleitwert τc τa Thermal cooling time constant Thermal time constant Thermische Abkühlzeitkonstante Thermische Zeitkonstante Abbreviations / Notes Symbol English German Surface-mounted devices Oberflächenmontierbares Bauelement * To be replaced by a number in ordering Platzhalter für Zahl im Bestellnummerncodes, type designations etc. code oder für die Typenbezeichnung. + To be replaced by a letter. Platzhalter für einen Buchstaben. All dimensions are given in mm. Alle Maße sind in mm angegeben. The commas used in numerical values denote decimal points. Verwendete Kommas in Zahlenwerten bezeichnen Dezimalpunkte. Please read Cautions and warnings and Important notes at the end of this document. Page 10 of 11 Important notes The following applies to all products named in this publication: 1. Some parts of this publication contain statements about the suitability of our products for certain areas of application. These statements are based on our knowledge of typical requirements that are often placed on our products in the areas of application concerned. We nevertheless expressly point out that such statements cannot be regarded as binding statements about the suitability of our products for a particular customer application. As a rule, EPCOS is either unfamiliar with individual customer applications or less familiar with them than the customers themselves. For these reasons, it is always ultimately incumbent on the customer to check and decide whether an EPCOS product with the properties described in the product specification is suitable for use in a particular customer application. 2. We also point out that in individual cases, a malfunction of electronic components or failure before the end of their usual service life cannot be completely ruled out in the current state of the art, even if they are operated as specified. In customer applications requiring a very high level of operational safety and especially in customer applications in which the malfunction or failure of an electronic component could endanger human life or health (e.g. in accident prevention or lifesaving systems), it must therefore be ensured by means of suitable design of the customer application or other action taken by the customer (e.g. installation of protective circuitry or redundancy) that no injury or damage is sustained by third parties in the event of malfunction or failure of an electronic component. 3. The warnings, cautions and product-specific notes must be observed. 4. In order to satisfy certain technical requirements, some of the products described in this publication may contain substances subject to restrictions in certain jurisdictions (e.g. because they are classed as hazardous). Useful information on this will be found in our Material Data Sheets on the Internet (www.epcos.com/material). Should you have any more detailed questions, please contact our sales offices. 5. We constantly strive to improve our products. Consequently, the products described in this publication may change from time to time. The same is true of the corresponding product specifications. Please check therefore to what extent product descriptions and specifications contained in this publication are still applicable before or when you place an order. We also reserve the right to discontinue production and delivery of products. Consequently, we cannot guarantee that all products named in this publication will always be available. The aforementioned does not apply in the case of individual agreements deviating from the foregoing for customer-specific products. 6. Unless otherwise agreed in individual contracts, all orders are subject to the current version of the "General Terms of Delivery for Products and Services in the Electrical Industry" published by the German Electrical and Electronics Industry Association (ZVEI). 7. The trade names EPCOS, BAOKE, Alu-X, CeraDiode, CSMP, CSSP, CTVS, DSSP, MiniBlue, MKK, MLSC, MotorCap, PCC, PhaseCap, PhaseCube, PhaseMod, SIFERRIT, SIFI, SIKOREL, SilverCap, SIMDAD, SIMID, SineFormer, SIOV, SIP5D, SIP5K, ThermoFuse, WindCap are trademarks registered or pending in Europe and in other countries. Further information will be found on the Internet at www.epcos.com/trademarks. Page 11 of 11