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- Maximum Continuous Use, 200°C (392°F) [Short Term Use to 250°C (482°F)]
- Excellent Long Term Stability
- Hermetically Sealed Glass Bead
- Available in 2252, 3000, 5000 and 10,000 Ω Resistances at 25°C (77°F)
- Tolerance: ±0.2°C From 0 to 70°C (32 to 158°F)
- 2.4 mm (0.095") Diameter Bead Max
- #32 AWG, Gold Plated Dumet Leads 63.5 mm (2.5") Long

Description

The OMEGA 55000 Series glass encapsulated thermistors provide a higher temperature alternative to the OMEGA 44000 Series epoxy coated thermistors where needed. With a maximum continuous temperature rating of -80 to 200°C (-112 to 392°F), and intermittent operation to 250°C (482°F), the 55000 Series thermistors can be used in those applications previously out of reach.With the same small size as our 44000 Series thermistor, and with solderable #32 AWG gold plated Dumet leads, the 55000 Series thermistor can be used interchangeably wherever our 44000 Series thermistors are used.

The Steinhart-Hart Equation has become the generally accepted method for specifying the resistance vs. temperature relationship for thermistors. The Steinhart-Hart equation for

where: A, B and C are constants derived from three temperature test points.

R = Thermistor resistance in Ω

T = Temperature in Kelvins K (°C + 275.15)

To determine the

R = e

where:

alpha = ((A-(1/T))/C)

Model Number | R25°C | A | B | C |
---|---|---|---|---|

55004 | 2252Ω | 1.4705x10^{-3} | 2.3780x10^{-4} | 1.0389x10^{-7} |

55005 | 3000Ω | 1.4052x10^{-3} | 2.3692x10^{-4} | 1.0125x10^{-7} |

55007 | 5000Ω | 1.2870x10^{-3} | 2.3585x10^{-4} | 9.4346x10^{-8} |

55016 | 10000Ω | 1.1275x10^{-3} | 2.3441x10^{-4} | 8.6482x10^{-8} |

The A, B and C constants for each of our thermistor selections are shown in the table to the right. Using these constants, you can determine the temperature of the thermistor based on its resistance, or determine a thermistor's resistance at a particular temperature.

Model No. 55016 Thermistor | |
---|---|

Operating Temperature | 10 Months |

0°C | <0.01°C |

25°C | <0.01°C |

100°C | <0.12°C |

150°C | <0.15°C |

200°C | <0.20°C |

Thermistors are generally very accurate and stable devices, but conditions such as over-temperature exposure, thermal or mechanical shock, or subjecting them to over-current conditions can result in a change in resistance. The 55000 Series thermistors are chemically stable and not significantly affected by aging. The following shows typical stability data for the 55016 thermistor:

Temp °C | Model No. 55004, ±0.20°C | |
---|---|---|

±°C | ±Ω | |

-80°C | 1.00 | 142,000 |

-40°C | 0.40 | 2018 |

0°C | 0.20 | 75 |

40°C | 0.20 | 10 |

70°C | 0.20 | 2.7 |

100°C | 0.30 | 1.3 |

150°C | 1.00 | 0.9 |

Accuracy tolerances for thermistor sensors are expressed as a percentage of temperature. This is also referred to as interchangeability. The 55000 Series thermistors do have a tolerance of ±0.2°C between 0 and 70°C, but can be used across their entire temperature range.

The suggested operating current for bead-style thermistors is approximately 10 to 15 micro-amps. thermistors can experience self-heating effects if they are exposed to operating currents that are high enough to create more heat than the thermistor can dissipate to its surroundings. The 55000 Series thermistors have a dissipation constant of 1.5 milliwatts/°C in air.

The time constant is the time required for a thermistor to react to a step change in temperature. For example, if exposed to a change from 0 to 100°C (32 to 212°F), the 63% time constant would be the time required for the thermistor to indicate a resistance to its value at 63°C (145°F). The time constant for the 55000 Series thermistor is less than 15 seconds in air.

† *All amounts shown in AUD*

*Ordering Example:* (1) **55007** Thermistor, 5000 ohms at 25°C (77°F), 2.4 mm (0.095, **AUD35.50**