GE Sensing Applications Description Thermobead and GC (chip-in-glass) assemblies are used NTC Type AB6 thermistor assemblies consist of small GC where the small thermistor must be further connected to (chip-in-glass) or Thermobeads that are welded to longer leads, for insertion into deep wells and cavities, or insulated extension leads. The Thermobeads or GC threading into long tubes. They may also be used, as is, (chip-in-glass) are hermetically sealed in glass and have for applications that require fast response measure- fine diameter 0.0007 in to 0.004 in (0.01778 mm to 0.1016 ments in confined spaces. With these assemblies, the mm) platinum alloy leads. The platinum leads are cut fast response of the small thermistor is available without short and welded to insulated extension leads and the sacrificing ease of insertion. The added leads and joints are covered in one of several insulation types, insulation allow the minute assemblies to be handled in depending upon the application or environment. The further assembly operations, such as insertion into assembly is then ready for insertion into hypodermic catheter lumens. The same electrical characteristics that needles, catheters or other small housings that require apply to the selected thermistor (resistance value, extended leads. Any of the Thermobeads or GC (chip-in- resistance ratio, stability) are unaltered in the assembly. glass) listed in Table I may be used in a NTC Type AB6 assembly. Please consult the data shown for specific electrical or mechanical properties for the thermistor selected. NTC Type AB6 Thermometrics Thermobeads and GCs (Chip-in-Glass) NTC Type AB6 is a Thermometrics product. Thermometrics has joined other GE high–technology sensing businesses under a new name—GE Sensing. g GE Sensing 0.13 in (3.2 mm) reference 72 in (1830 mm) minimum NTC Type AB6 D Specifications Type C Insulation Type A Insulation AB6C8 Thermistor bead is welded to 38 gauge, nickel alloy 200, AB6A8 bifilar, heavy ISONEL insulated extension leads, 6.5 ft Thermistor is welded to 38 gauge, nickel alloy 200, bifilar (1.98 m) ±0.5 ft (±0.15 m) long. Multiple conformal heavy ISONEL insulated extension leads, 6.5 ft (1.98 m) dipcoats of liquid epoxy resin are applied for complete ±0.5 ft (±0.15 m) long. Liquid epoxy resin web over weld insulation when immersed in fluids. joints provides some strain relief. For use where fastest response times are required and For insertion into plastic tubing or other insulators. assembly will be fully immersed in conductive fluids. Maximum continuous operating temperature is 221°F Maximum continuous operating temperature is 221°F (105ºC). (105°C). 0.13 in (3.2 mm) reference 72 in (1830 mm) minimum 72 in (1830 mm) minimum 0.25 in (6.4 mm) reference D D Type B Insulation Type D Insulation AB6B2 AB6D2 Thermistors welded to 38 gauge, nickel alloy 200, bifilar, Thermistor is welded to 38 gauge, nickel alloy 200, bifilar, heavy ISONEL insulated extension leads, 6.5 ft (1.98 m) heavy ISONEL insulated extension leads, 6.5 ft (1.98 m) ±1/2 ft (±0.15 m) long. Polyimide sleeve is epoxied over ±0.5 ft (±0.15 m) long. Small web of epoxy is painted over weld joints and thermistor, for strain relief and insulation. weld joints for electrical isolation and strain relief, and a heat sealed mylar sheath covers the bead. For insertion into metal housings or tubings. Bead covered for maximum strain relief and protection. For fast response times, limited depth of immersion, and Maximum continuous operating temperature is 347°F best long term immersion qualities. Maximum continuous (175ºC). operating temperature is 257°F (125°C). 0.13 in (3.2 mm) reference 72 in (1830 mm) minimum 1.5 in (38 mm) reference 72 in (1830 mm) minimum D D AB6B4 Thermistor is welded to 38 gauge, nickel alloy 200, bifilar, Type E Insulation heavy ISONEL insulated extension leads, 6.5 ft (1.98 m) ±0.5 ft (±0.15 m) long. Polyimide sleeve is epoxied over AB6E3 weld joints and up to back of thermistor bead, for strain Thermistor is welded to 38 gauge, nickel alloy 200, bifilar, relief and electrical insulation. heavy ISONEL insulated extension leads 6.5 ft (1.98 m) ±0.5 ft (±0.15 m) long. Polyimide sleeve is epoxied over For insertion into metal housings or tubings with close welds for strain relief and electrical insulation, multiple tolerances. Bead is exposed as much as possible for conformal dip coatings of liquid epoxy resin are applied faster response. Maximum continuous operating for complete immersibility in conductive fluids. temperature is 221°F (105ºC). GE Sensing For use in applications where fast response, good strain 2) Select one of the assembly types shown and use the relief and full immersion are required. Maximum assembly prefix listed for that type followed by the continuous operating temperature is 221°F (105ºC). thermistor part number. Example: AB6A8-BR16KA103N 0.25 in (6.4 mm) reference 72 in (1830 mm) minimum This assembly uses a 0.016 in (0.40 mm) nominal diameter, 0.13 in (3.2 mm) reference ruggedized Thermobead (Refer to NTC Type BR Series datasheet) with adjacent cut leads, 10 kΩ ±25% at 77°F D (25°C) nominal resistance, welded to standard 6.5 (1.98 m) ±0.5 ft (±0.15 m) long, 38 gauge, nickel alloy 200, bifilar, heavy ISONEL insulated extension leads with epoxy resin web between the welded joints for strain relief. AB6E5 Thermistor is welded to 38 gauge, nickel alloy 200, bifilar, Special Coding heavy ISONEL insulated extension leads, 6.5 ft (1.98 m) ±0.5 ft (±0.15 m) long. Polyimide sleeve is epoxied over bead and weld joints for strain relief and insulation. Liquid The assembly types shown represent the most standard epoxy resin conformal dipcoats are applied for moisture selections of the many combinations of thermistors and sealing. materials that GE manufactures. These selected types are suitable for many applications; however, there are always special requirements that need to be satisfied for some For use where assembly will be subjected to limited fluid applications. A partial listing of alternate materials and immersions and where maximum strain relief is also options is given on the next page to assist the designer required with minimum outside diameter. Maximum for applications in which the standard units shown are continuous operating temperature is 221°F (105°C). not suitable. If assistance is required in the selection of materials or design of the assembly, please contact our 72 in (1830 mm) minimum 0.13 in (3.2 mm) reference applications engineering department and detail the exact requirements or specifications desired. D Alternate Materials Selection The alternate materials listed are available for NTC Type AB6 thermistor assembly orders. Other materials may be available to the designer or user upon special order. AB6E8 Please allow additional time for the completion of special Thermistor is welded to 38 gauge, nickel alloy 200, bifilar, assembly orders. heavy ISONEL insulated extension leads 6.5 ft (1.98 m) ±0.5 ft (±0.15 m) long. Polyimide sleeve is epoxied over welds and thermistor for strain relief and electrical insulation. Type A Insulations Multiple conformal dip coatings of liquid epoxy resin are A web of insulating material is put over the weld joints for applied for complete immersibility in conductive fluids. strain relief. Available insulating materials with maximum temperature ratings; For use in applications where superior strain relief and full immersion are required. Maximum continuous operating • Vinyl: 140°F (60°C) temperature is 221°F (105°C). • Polyurethane: 221°F (105°C) • Silicone rubber: 500°F (260°C) 0.25 in (6.4 mm) reference 72 in (1830 mm) minimum • Epoxies: from 221°F to 500°F (105°C to 260°C), specify 0.13 in (3.2 mm) reference maximum temperature required. D Type B Insulations A polyimide sleeve is epoxied over the weld joints for improved strain relief and electrical insulation. The bead may be covered for maximum strain relief or exposed for faster response. Epoxies are generally used to fill the Coding polyimide sleeve and have temperature ratings from 221°F to 500°F (105°C to 260°C). 1) Select the appropriate thermistor bead or small probe from one of the thermistor types shown in Table 1. Refer to the appropriate datasheet for electrical and mechanical properties of the thermistor selected and specific ordering information for that thermistor. GE Sensing Type C Insulations Construction Multiple conformal dip coats over the thermistor and • Bifilar: Parallel conductors, our standard welds are used in order to provide fully immersible • Single: Individually insulated lead-wires assemblies. Any of the Type A insulating materials may • Twisted Pair: 0.1 in (2.54 mm) lay typical be used for the conformal dip coatings depending upon the application or environment. Length 6.5 ft (1.98 m) ±0.5 ft (±0.15 m) is standard, specify other Type D Insulations lengths as desired. All lengths over one foot are supplied A thermoplastic tubing is heat sealed over the bead or on a plastic bobbin with the wires wrapped so that the probe thermistor. A small amount of insulating material is thermistor end is removed last. applied over the weld joints for electrical isolation. The assembly is not fully immersible over the back end of the Table 1: Standard Sizes of tubing. Available heat sealed tubing materials with maximum temperature ratings: NTC Type AB6 Thermistor Assemblies • Polyethylene: 176°F (80°C) Thermistor Maximum Maximum Diameter of Assembly • Mylar: 257°F (125°C) Type Thermistor Diameter in (mm) A8 B2 B4 C8 D2 E3 E5 E8 Type E Insulations BR11 0.012 0.014 0.018 0.014 0.022 0.034 0.020 0.022 0.024 A polyimide sleeve is epoxied over the weld joints (as in (0.30) (0.35) (0.45) (0.35) (0.55) (0.86) (0.50) (0.55) (0.60) BR14 0.016 0.016 0.021 0.016 0.024 0.036 0.022 0.025 0.027 the Type B insulations) and then multiple conformal dip (0.40) (0.40) (0.53) (0.40) (0.60) (0.91) (0.55) (0.63) (0.68) coatings are applied (as in the Type C insulations) for fully BR16 0.017 0.017 0.022 0.017 0.025 0.037 0.023 0.026 0.028 immersible assemblies. The same insulating material (0.43) (0.43) (0.55) (0.43) (0.63) (0.93) (0.58) (0.66) (0.71) options are available. BR23 0.025 0.025 0.032 0.025 0.033 0.045 0.031 0.036 0.038 (0.63) (0.63) (0.81) (0.63) (0.83) (1.14) (0.78) (0.91) (0.96) BR32 0.033 0.033 0.040 0.033 0.041 0.053 0.039 0.044 0.046 Insulated Extension Leads (0.83) (0.83) (1.01) (0.83) (1.04) (1.34) (0.99) (1.11) (1.16) The standard insulated extension lead sub assembly has BR42 0.046 0.046 0.053 0.046 0.054 0.066 0.052 0.057 0.059 (1.16) (1.16) (1.34) (1.16) (1.37) (1.67) (1.32) (1.44) (1.49) 38 gauge 0.004 in (0.10 mm) diameter, nickel alloy 200, BR55 0.060 0.060 0.070 0.060 0.068 0.080 0.066 0.074 0.076 bifilar, heavy ISONEL insulation over conductors and a (1.52) (1.52) (1.77) (1.52) (1.72) (2.03) (1.67) (1.87) (1.93) length of 6.5 (1.98 m) ±1/2 ft (±0.15 m). Other options, GC 11 0.012 0.014 0.018 0.014 0.022 0.034 0.020 0.022 0.024 including any specified by the customer, are available (0.30) (0.35) (0.45) (0.35) (0.55) (0.86) (0.50) (0.55) (0.50) GC 14 0.016 0.016 0.021 0.016 0.024 0.036 0.022 0.026 0.027 upon special order. (0.40) (0.40) (0.53) (0.40) (0.60) (0.93) (0.55) (0.63) (0.68) GC 16 0.017 0.017 0.022 0.017 0.025 0.037 0.023 0.026 0.028 (0.43) (0.43) (0.55) (0.43) (0.63) (0.93) (0.58) (0.66) (0.71) Wire Gauges GC 32 0.033 0.033 0.040 0.033 0.041 0.053 0.039 0.044 0.046 #38 GA 0.004 in (0.10 mm), #40GA 0.0031 in (0.079 mm) (0.83) (0.83) (1.01) (0.83) (1.04) (1.34) (0.99) (1.11) (1.16) Conductors Nickel alloy 200 Insulation • Heavy ISONEL: for use to 356°F (180°C), excellent abrasion resistance, our standard coating. • Polyurethane: for use to 221°F (105°C), easily stripped, excellent solderability. • Polyimide: for use to 446°F (230°C), excellent thermal and dielectric properties, (not recommended for water and certain other conductive fluids) ©2007 GE. All rights reserved. 920-254B www.gesensing.com All specifications are subject to change for product improvement without notice. ® GE is a registered trademark of General Electric Co. 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