B57540G1104F000

NTC thermistors for temperature measurement Glass-encapsulated sensors, standard type Series/Type: Date: B57540G, B57540G1 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 Glass-encapsulated sensors B57540G, B57540G1 G540/G1540 Applications Temperature measurement Features Glass-encapsulated, heat-resistive and highly stable For temperature measurement up to 250 °C Very short response time Small dimensions Leads: dumet wires (copper-clad FeNi) Options Leads: nickel-plated dumet wires Alternative dimensions available on request Delivery mode Bulk General technical data Climatic category Max. power Resistance tolerance Rated temperature Dissipation factor Thermal cooling time constant Heat capacity (IEC 60068-1) (at 25 °C) Dimensional drawing Dimensions in mm (in air) (in air) P25 ∆RR/RR TR δth τc Cth 55/250/56 18 ±1, ±2, ±3 25 approx. 0.4 approx. 3 approx. 1.3 mW % °C mW/K s mJ/K Please read Cautions and warnings and Important notes at the end of this document. Page 2 of 18 Temperature measurement Glass-encapsulated sensors B57540G, B57540G1 G540/G1540 Electrical specification and ordering codes R25 Ω 5k 5k 10 k 10 k 10 k 10 k 20 k 20 k 30 k 30 k 50 k 50 k 100 k 100 k 230 k 230 k 1400 k 1400 k No. of R/T characteristic 8402 8402 7003 7003 8307 8307 8415 8415 7002 7002 8403 8403 8304 8304 8405 8405 8406 8406 B25/85 K 3480 3480 3612 3612 3478 3478 3992 3992 3973 3973 3992 3992 4072 4072 4240 4240 4557 4557 B0/100 K 3450 ±1% 3450 ±1% 3586 3586 3450 3450 3970 ±1% 3970 ±1% 3944 3944 3970 ±1% 3970 ±1% 4036 4036 4537 ±2%1) 4537 ±2%1) 5133 ±2%2) 5133 ±2%2) B25/100 K 3497 3497 3625 ±1% 3625 ±1% 3492 ±1% 3492 ±1% 4006 4006 3988 ±1% 3988 ±1% 4006 4006 4092 ±1% 4092 ±1% 4264 4264 4581 4581 Ordering code B57540G0502+000 B57540G0502+002 B57540G1103+005 B57540G1103+007 B57540G1103+000 B57540G1103+002 B57540G0203+000 B57540G0203+002 B57540G1303+005 B57540G1303+007 B57540G0503+000 B57540G0503+002 B57540G1104+000 B57540G1104+002 B57540G0234+000 B57540G0234+002 B57540G0145+000 B57540G0145+002 + = Resistance tolerance F = ±1% G = ±2% H = ±3% The last three digits of the ordering code denote: 000 and 005 = dumet wires 002 and 007 = nickel-plated wires 1) B100/200 2) B200/300 Please read Cautions and warnings and Important notes at the end of this document. Page 3 of 18 Temperature measurement Glass-encapsulated sensors B57540G, B57540G1 G540/G1540 Reliability data Test Storage in dry heat Standard IEC 60068-2-2 Test conditions ∆R25/R25 (typical) < 3% Remarks No visible damage Storage in damp heat, steady state Rapid temperature cycling Storage at upper category temperature T: 250 °C t: 1000 h IEC Temperature of air: 85 °C 60068-2-67 Relative humidity of air: 85% Duration: 56 days IEC Lower test temperature: 55 °C 60068-2-14 Upper test temperature: 200 °C Number of cycles: 1000 < 2% No visible damage No visible damage < 2% Please read Cautions and warnings and Important notes at the end of this document. Page 4 of 18 Temperature measurement Glass-encapsulated sensors B57540G, B57540G1 G540/G1540 R/T characteristics R/T No. T (°C) 55.0 50.0 45.0 40.0 35.0 30.0 25.0 20.0 15.0 10.0 5.0 0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0 40.0 45.0 50.0 55.0 60.0 65.0 70.0 75.0 80.0 85.0 90.0 95.0 100.0 105.0 110.0 115.0 120.0 125.0 130.0 135.0 140.0 145.0 150.0 155.0 7002 7003 8304 B25/100 = 3988 K B25/100 = 3625 K B25/100 = 4092 K RT/R25 α (%/K) RT/R25 α (%/K) RT/R25 α (%/K) 96.33 66.866 47.037 33.508 24.156 17.613 12.98 9.6643 7.2656 5.5129 4.22 3.2575 2.5348 1.9876 1.5699 1.2488 1.0000 0.80594 0.65355 0.53312 0.43735 0.36074 0.29911 0.24925 0.20872 0.17558 0.14837 0.12592 0.10731 0.091816 0.078862 0.067988 0.058824 0.051071 0.044489 0.03888 0.034084 0.02997 0.02643 0.023373 0.020727 0.018429 0.016427 7.4 7.2 6.9 6.7 6.4 6.2 6.0 5.8 5.6 5.4 5.3 5.1 4.9 4.8 4.6 4.5 4.4 4.3 4.1 4.0 3.9 3.8 3.7 3.6 3.5 3.4 3.3 3.2 3.2 3.1 3.0 2.9 2.9 2.8 2.7 2.7 2.6 2.5 2.5 2.4 2.4 2.3 2.3 63.225 45.46 33.07 24.324 18.081 13.575 10.29 7.8716 6.0739 4.7258 3.7062 2.9287 2.3311 1.8684 1.5075 1.224 1.0000 0.82176 0.67909 0.56422 0.47122 0.3955 0.33355 0.2826 0.24049 0.20553 0.17637 0.15195 0.13141 0.11406 0.099352 0.086837 0.076149 0.066989 0.059112 0.052316 0.046433 0.041327 0.03688 0.032998 0.029598 0.026612 0.023984 6.7 6.5 6.3 6.0 5.8 5.6 5.4 5.3 5.1 4.9 4.8 4.6 4.5 4.4 4.2 4.1 4.0 3.9 3.8 3.7 3.6 3.5 3.4 3.3 3.2 3.1 3.0 2.9 2.9 2.8 2.7 2.7 2.6 2.5 2.5 2.4 2.4 2.3 2.3 2.2 2.2 2.1 2.1 100.11 69.56 48.945 34.853 25.102 18.275 13.443 9.9853 7.4867 5.6636 4.3212 3.324 2.5769 2.0127 1.5834 1.2542 1.0000 0.80239 0.64776 0.52598 0.4295 0.35262 0.291 0.24136 0.20114 0.16841 0.14164 0.11963 0.10147 0.086407 0.073867 0.063383 0.054584 0.04717 0.040901 0.035581 0.03105 0.027179 0.023861 0.021008 0.018548 0.016419 0.014573 7.4 7.2 6.9 6.7 6.5 6.2 6.0 5.9 5.7 5.5 5.3 5.2 5.0 4.9 4.7 4.6 4.5 4.3 4.2 4.1 4.0 3.9 3.8 3.7 3.6 3.5 3.4 3.3 3.3 3.2 3.1 3.0 3.0 2.9 2.8 2.8 2.7 2.6 2.6 2.5 2.5 2.4 2.4 Please read Cautions and warnings and Important notes at the end of this document. Page 5 of 18 Temperature measurement Glass-encapsulated sensors B57540G, B57540G1 G540/G1540 R/T No. T (°C) 160.0 165.0 170.0 175.0 180.0 185.0 190.0 195.0 200.0 205.0 210.0 215.0 220.0 225.0 230.0 235.0 240.0 245.0 250.0 255.0 260.0 265.0 270.0 275.0 280.0 285.0 290.0 295.0 300.0 7002 7003 8304 B25/100 = 3988 K B25/100 = 3625 K B25/100 = 4092 K RT/R25 α (%/K) RT/R25 α (%/K) RT/R25 α (%/K) 0.014679 2.2 0.021665 2.0 0.012967 2.3 0.013149 2.2 0.019613 2.0 0.011566 2.3 0.011806 0.010623 0.0095804 0.0086582 0.0078408 0.0071148 0.0064685 0.005892 0.0053767 0.0049152 0.0045011 0.0041287 0.0037934 0.0034908 0.0032173 0.0029697 0.0027451 0.0025412 0.0023556 0.0021865 0.0020323 0.0018913 0.0017623 0.0016441 0.0015357 0.001436 0.0013444 2.1 2.1 2.0 2.0 2.0 1.9 1.9 1.8 1.8 1.8 1.7 1.7 1.7 1.6 1.6 1.6 1.6 1.5 1.5 1.5 1.5 1.4 1.4 1.4 1.4 1.3 1.3 0.017793 0.016176 0.014735 0.013448 0.012297 0.011265 0.010338 0.009504 0.0087516 0.0080718 0.0074567 0.0068989 0.0063925 0.0059318 0.005512 0.005129 0.004779 0.0044586 0.004165 0.0038955 0.0036478 0.0034199 0.0032098 0.003016 0.002837 0.0026714 0.002518 1.9 1.9 1.8 1.8 1.8 1.7 1.7 1.7 1.6 1.6 1.6 1.5 1.5 1.5 1.5 1.4 1.4 1.4 1.4 1.3 1.3 1.3 1.3 1.2 1.2 1.2 1.2 0.010341 0.0092664 0.0083224 0.0074907 0.0067564 0.0061064 0.0055299 0.0050175 0.0045611 0.0041537 0.0037895 0.0034631 0.0031701 0.0029067 0.0026693 0.0024551 0.0022615 0.0020862 0.0019273 0.0017829 0.0016516 0.0015319 0.0014228 0.0013231 0.0012319 0.0011483 0.0010716 2.2 2.2 2.1 2.1 2.0 2.0 2.0 1.9 1.9 1.9 1.8 1.8 1.8 1.7 1.7 1.7 1.6 1.6 1.6 1.5 1.5 1.5 1.5 1.4 1.4 1.4 1.4 Please read Cautions and warnings and Important notes at the end of this document. Page 6 of 18 Temperature measurement Glass-encapsulated sensors B57540G, B57540G1 G540/G1540 R/T characteristics R/T No. T (°C) 55.0 50.0 45.0 40.0 35.0 30.0 25.0 20.0 15.0 10.0 5.0 0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0 40.0 45.0 50.0 55.0 60.0 65.0 70.0 75.0 80.0 85.0 90.0 95.0 100.0 105.0 110.0 115.0 120.0 125.0 130.0 135.0 140.0 145.0 150.0 155.0 8307 8402 8403 B25/100 = 3492 K B0/100 = 3450 K B0/100 = 3970 K RT/R25 α (%/K) RT/R25 α (%/K) RT/R25 α (%/K) 52.624 38.452 28.401 21.194 15.972 12.149 9.3246 7.2181 5.6332 4.4308 3.5112 2.8024 2.252 1.8216 1.4827 1.2142 1.0000 0.82818 0.68954 0.57703 0.48525 0.41 0.34798 0.29663 0.25392 0.21824 0.1883 0.16307 0.14174 0.12362 0.10818 0.094973 0.08364 0.073881 0.06545 0.058144 0.051794 0.046259 0.04142 0.037179 0.033451 0.030166 0.027264 6.4 6.2 6.0 5.8 5.6 5.4 5.2 5.0 4.9 4.7 4.6 4.4 4.3 4.2 4.1 3.9 3.8 3.7 3.6 3.5 3.4 3.3 3.2 3.2 3.1 3.0 2.9 2.8 2.8 2.7 2.6 2.6 2.5 2.5 2.4 2.3 2.3 2.2 2.2 2.1 2.1 2.0 2.0 51.991 37.989 28.07 20.96 15.809 12.037 9.2484 7.1668 5.5993 4.4087 3.4971 2.7936 2.2468 1.8187 1.4813 1.2136 1.0000 0.82845 0.68991 0.57742 0.4856 0.41026 0.34816 0.29673 0.25393 0.21817 0.18816 0.16288 0.1415 0.12335 0.10788 0.094659 0.083313 0.073547 0.065114 0.05781 0.051464 0.045936 0.041106 0.036875 0.033159 0.029886 0.026998 6.4 6.2 5.9 5.7 5.5 5.4 5.2 5.0 4.9 4.7 4.6 4.4 4.3 4.2 4.0 3.9 3.8 3.7 3.6 3.5 3.4 3.3 3.2 3.2 3.1 3.0 2.9 2.8 2.8 2.7 2.6 2.6 2.5 2.5 2.4 2.4 2.3 2.2 2.2 2.1 2.1 2.1 2.0 103.29 71.079 49.619 35.108 25.158 18.245 13.383 9.9221 7.4316 5.6202 4.2894 3.3024 2.5607 2.0017 1.5768 1.2513 1.0000 0.80451 0.65139 0.53064 0.43481 0.35828 0.29681 0.24715 0.20682 0.17389 0.14687 0.12459 0.10614 0.09078 0.077949 0.067183 0.058113 0.050443 0.043932 0.038386 0.033645 0.029579 0.02608 0.02306 0.020446 0.018176 0.016199 7.6 7.3 7.1 6.8 6.5 6.3 6.1 5.9 5.7 5.5 5.3 5.2 5.0 4.8 4.7 4.6 4.4 4.3 4.2 4.0 3.9 3.8 3.7 3.6 3.5 3.4 3.3 3.2 3.2 3.1 3.0 2.9 2.9 2.8 2.7 2.7 2.6 2.5 2.5 2.4 2.4 2.3 2.3 Please read Cautions and warnings and Important notes at the end of this document. Page 7 of 18 Temperature measurement Glass-encapsulated sensors B57540G, B57540G1 G540/G1540 R/T No. T (°C) 160.0 165.0 170.0 175.0 180.0 185.0 190.0 195.0 200.0 205.0 210.0 215.0 220.0 225.0 230.0 235.0 240.0 245.0 250.0 255.0 260.0 265.0 270.0 275.0 280.0 285.0 290.0 295.0 300.0 8307 8402 8403 B25/100 = 3492 K B0/100 = 3450 K B0/100 = 3970 K RT/R25 α (%/K) RT/R25 α (%/K) RT/R25 α (%/K) 0.024694 2.0 0.024442 2.0 0.014473 2.2 0.022414 1.9 0.022175 1.9 0.012962 2.2 0.020385 0.018577 0.016961 0.015514 0.014216 0.013049 0.011999 0.011051 0.010194 0.0094181 0.0087144 0.0080751 0.0074933 0.0069631 0.0064791 0.0060366 0.0056316 0.0052602 0.0049193 0.0046059 0.0043173 0.0040514 0.003806 0.0035793 0.0033696 0.0031753 0.0029952 1.9 1.8 1.8 1.8 1.7 1.7 1.7 1.6 1.6 1.6 1.5 1.5 1.5 1.5 1.4 1.4 1.4 1.4 1.3 1.3 1.3 1.3 1.2 1.2 1.2 1.2 1.2 0.02016 0.018365 0.016762 0.015328 0.014043 0.012888 0.011849 0.010913 0.010067 0.0093013 0.0086075 0.0079777 0.007405 0.0068833 0.0064075 0.0059728 0.0055751 0.0052107 0.0048764 0.0045692 0.0042866 0.0040263 0.0037862 0.0035645 0.0033595 0.0031697 0.0029938 1.9 1.8 1.8 1.8 1.7 1.7 1.7 1.6 1.6 1.6 1.5 1.5 1.5 1.4 1.4 1.4 1.4 1.3 1.3 1.3 1.3 1.2 1.2 1.2 1.2 1.2 1.1 0.011636 0.010469 0.0094395 0.0085294 0.0077229 0.0070067 0.0063691 0.0058005 0.0052924 0.0048373 0.004429 0.004062 0.0037315 0.0034333 0.0031639 0.00292 0.0026988 0.002498 0.0023153 0.0021489 0.0019971 0.0018584 0.0017316 0.0016153 0.0015087 0.0014107 0.0013207 2.1 2.1 2.0 2.0 2.0 1.9 1.9 1.9 1.8 1.8 1.7 1.7 1.7 1.6 1.6 1.6 1.6 1.5 1.5 1.5 1.5 1.4 1.4 1.4 1.4 1.3 1.3 Please read Cautions and warnings and Important notes at the end of this document. Page 8 of 18 Temperature measurement Glass-encapsulated sensors B57540G, B57540G1 G540/G1540 R/T characteristics R/T No. T (°C) 55.0 50.0 45.0 40.0 35.0 30.0 25.0 20.0 15.0 10.0 5.0 0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0 40.0 45.0 50.0 55.0 60.0 65.0 70.0 75.0 80.0 85.0 90.0 95.0 100.0 105.0 110.0 115.0 120.0 125.0 130.0 135.0 140.0 145.0 150.0 155.0 8405 8406 8415 B100/200 = 4537 K B200/300 = 5133 K B0/100 = 3970 K RT/R25 α (%/K) RT/R25 α (%/K) RT/R25 α (%/K) 122.12 83.306 57.62 40.378 28.647 20.563 14.925 10.947 8.1101 6.0655 4.5776 3.4845 2.6743 2.0686 1.6121 1.2654 1.0000 0.79548 0.63677 0.51279 0.41534 0.33828 0.27698 0.22795 0.18853 0.15666 0.13077 0.10964 0.092319 0.078049 0.066244 0.056439 0.048262 0.041416 0.035663 0.030811 0.026705 0.023218 0.020247 0.017707 0.01553 0.013658 0.012043 7.8 7.5 7.2 7.0 6.7 6.5 6.3 6.1 5.9 5.7 5.5 5.4 5.2 5.1 4.9 4.8 4.6 4.5 4.4 4.3 4.2 4.1 3.9 3.8 3.7 3.7 3.6 3.5 3.4 3.3 3.2 3.2 3.1 3.0 3.0 2.9 2.8 2.8 2.7 2.7 2.6 2.5 2.5 183.3 120.69 80.721 54.792 37.713 26.301 18.571 13.269 9.5865 6.9997 5.1625 3.844 2.8884 2.1892 1.673 1.2886 1.0000 0.78164 0.61516 0.48734 0.38851 0.3116 0.25136 0.2039 0.16629 0.1363 0.11228 0.092932 0.077268 0.064527 0.054116 0.045571 0.038526 0.032694 0.027847 0.023803 0.020416 0.017569 0.015167 0.013135 0.011409 0.0099385 0.0086821 8.5 8.2 7.9 7.6 7.3 7.1 6.8 6.6 6.4 6.2 6.0 5.8 5.6 5.5 5.3 5.1 5.0 4.9 4.7 4.6 4.5 4.4 4.2 4.1 4.0 3.9 3.8 3.7 3.6 3.6 3.5 3.4 3.3 3.2 3.2 3.1 3.0 3.0 2.9 2.8 2.8 2.7 2.7 103.29 71.079 49.619 35.108 25.158 18.245 13.383 9.9221 7.4316 5.6202 4.2894 3.3024 2.5607 2.0017 1.5768 1.2513 1.0000 0.80451 0.65139 0.53064 0.43481 0.35828 0.29681 0.24715 0.20682 0.17389 0.14687 0.12459 0.10614 0.09078 0.077949 0.067183 0.058113 0.050443 0.043932 0.038386 0.033645 0.029579 0.02608 0.02306 0.020446 0.018176 0.016199 7.6 7.3 7.1 6.8 6.5 6.3 6.1 5.9 5.7 5.5 5.3 5.2 5.0 4.8 4.7 4.6 4.4 4.3 4.2 4.0 3.9 3.8 3.7 3.6 3.5 3.4 3.3 3.2 3.2 3.1 3.0 2.9 2.9 2.8 2.7 2.7 2.6 2.5 2.5 2.4 2.4 2.3 2.3 Please read Cautions and warnings and Important notes at the end of this document. Page 9 of 18 Temperature measurement Glass-encapsulated sensors B57540G, B57540G1 G540/G1540 R/T No. T (°C) 160.0 165.0 170.0 175.0 180.0 185.0 190.0 195.0 200.0 205.0 210.0 215.0 220.0 225.0 230.0 235.0 240.0 245.0 250.0 255.0 260.0 265.0 270.0 275.0 280.0 285.0 290.0 295.0 300.0 8405 8406 8415 B100/200 = 4537 K B200/300 = 5133 K B0/100 = 3970 K RT/R25 α (%/K) RT/R25 α (%/K) RT/R25 α (%/K) 0.010647 2.4 0.0076052 2.6 0.014473 2.2 0.009436 2.4 0.0066796 2.6 0.012962 2.2 0.0083831 0.0074652 0.006663 0.0059602 0.0053431 0.0047999 0.0043208 0.0038972 0.0035219 0.0031888 0.0028925 0.0026284 0.0023925 0.0021816 0.0019925 0.0018227 0.00167 0.0015324 0.0014083 0.0012961 0.0011946 0.0011025 0.0010189 0.00094294 0.00087373 2.3 2.3 2.3 2.2 2.2 2.1 2.1 2.0 2.0 2.0 1.9 1.9 1.9 1.8 1.8 1.8 1.7 1.7 1.7 1.6 1.6 1.6 1.6 1.5 1.5 0.0058817 0.005192 0.0045943 0.0040749 0.0036225 0.0032274 0.0028817 0.0025783 0.0023116 0.0020766 0.0018691 0.0016854 0.0015226 0.001378 0.0012492 0.0011344 0.0010318 0.00094005 0.00085777 0.00078388 0.00071742 0.00065754 0.00060352 0.0005547 0.00051051 2.5 2.5 2.4 2.4 2.3 2.3 2.2 2.2 2.2 2.1 2.1 2.0 2.0 2.0 1.9 1.9 1.9 1.8 1.8 1.8 1.8 1.7 1.7 1.7 1.6 0.011636 0.010469 0.0094395 0.0085294 0.0077229 0.0070067 0.0063691 0.0058005 0.0052924 0.0048373 0.004429 0.004062 0.0037315 0.0034333 0.0031639 0.00292 0.0026988 0.002498 0.0023153 0.0021489 0.0019971 0.0018584 0.0017316 0.0016153 0.0015087 0.0014107 0.0013207 2.1 2.1 2.0 2.0 2.0 1.9 1.9 1.9 1.8 1.8 1.7 1.7 1.7 1.6 1.6 1.6 1.6 1.5 1.5 1.5 1.5 1.4 1.4 1.4 1.4 1.3 1.3 0.00081063 1.5 0.00075301 1.5 0.00047047 1.6 0.00043412 1.6 Please read Cautions and warnings and Important notes at the end of this document. Page 10 of 18 Temperature measurement Glass-encapsulated sensors B57540G, B57540G1 G540/G1540 Mounting instructions 1 1.1 Soldering Leaded NTC thermistors Leaded thermistors comply with the solderability requirements specified by CECC. When soldering, care must be taken that the NTC thermistors are not damaged by excessive heat. The following maximum temperatures, maximum time spans and minimum distances have to be observed: Dip soldering Bath temperature Soldering time Distance from thermistor max. 260 °C max. 4 s min. 6 mm Iron soldering max. 360 °C max. 2 s min. 6 mm Under more severe soldering conditions the resistance may change. 1.2 Leadless NTC thermistors In case of NTC thermistors without leads, soldering is restricted to devices which are provided with a solderable metallization. The temperature shock caused by the application of hot solder may produce fine cracks in the ceramic, resulting in changes in resistance. To prevent leaching of the metallization, solder with silver additives or with a low tin content should be used. In addition, soldering methods should be employed which permit short soldering times. 2 Clamp contacting Pressure contacting by means of clamps is particularly suitable for applications involving frequent switching and high turn-on powers. 3 Robustness of terminations (leaded types) The leads meet the requirements of IEC 60068-2-21. They may not be bent closer than 4 mm from the solder joint on the thermistor body or from the point at which they leave the feedthroughs. During bending, any mechanical stress at the outlet of the leads must be removed. The bending radius should be at least 0.75 mm. Tensile strength: Test Ua1: Leads 0.25 < 0.35 < 0.50 < 0.80 < ∅ ≤0.25 mm = 1.0 N ∅ ≤0.35 mm = 2.5 N ∅ ≤0.50 mm = 5.0 N ∅ ≤0.80 mm = 10.0 N ∅ ≤1.25 mm = 20.0 N Please read Cautions and warnings and Important notes at the end of this document. Page 11 of 18 Temperature measurement Glass-encapsulated sensors B57540G, B57540G1 G540/G1540 Bending strength: Test Ub: Two 90°-bends in opposite directions at a weight of 0.25 kg. Torsional strength: Test Uc: severity 2 The lead is bent by 90° at a distance of 6 to 6.5 mm from the thermistor body. The bending radius of the leads should be approx. 0.75 mm. Two torsions of 180° each (severity 2). When subjecting leads to mechanical stress, the following should be observed: Tensile stress on leads During mounting and operation tensile forces on the leads are to be avoided. Bending of leads Bending of the leads directly on the thermistor body is not permissible. A lead may be bent at a minimum distance of twice the wire's diameter +2 mm from the solder joint on the thermistor body. During bending the wire must be mechanically relieved at its outlet. The bending radius should be at least 0.75 mm. Twisting of leads The twisting (torsion) by 180° of a lead bent by 90° is permissible at 6 mm from the bottom of the thermistor body. 4 Sealing and potting When thermistors are sealed, potted or overmolded, there must be no mechanical stress caused by thermal expansion during the production process (curing / overmolding process) and during later operation. The upper category temperature of the thermistor must not be exceeded. Ensure that the materials used (sealing / potting compound and plastic material) are chemically neutral. 5 Cleaning If cleaning is necessary, mild cleaning agents such as ethyl alcohol and cleaning gasoline are recommended. Cleaning agents based on water are not allowed. Ultrasonic cleaning methods are permissible. 6 Storage In order to maintain their solderability, thermistors must be stored in a non-corrosive atmosphere. Humidity, temperature and container materials are critical factors. Do not store SMDs where they are exposed to heat or direct sunlight. Otherwise, the packing material may be deformed or SMDs may stick together, causing problems during mounting. After opening the factory seals, such as polyvinyl-sealed packages, use the SMDs as soon as possible. Please read Cautions and warnings and Important notes at the end of this document. Page 12 of 18 Temperature measurement Glass-encapsulated sensors B57540G, B57540G1 G540/G1540 The components should be left in the original packing. Touching the metallization of unsoldered thermistors may change their soldering properties. Storage temperature: Relative humidity (without condensation): 25 °C up to 45 °C ≤75% annual mean