44004 Epoxy Coated Thermistor Elements

 Supported Applications

The Omega 44000 Series consists of epoxy-coated thermistor elements designed for temperature measurement. These precision-matched sensors feature resistance curves defined by the Steinhart-Hart equation, with constants provided in Table 1 of the series documentation.

Operating Conditions & Performance

The series supports two maximum working temperatures: 75°C (165°F) and 150°C (300°F). Corresponding operating temperature ranges are documented as -80 to 75°C (-110 to 165°F) for the lower-temperature models and -80 to 150°C (-110 to 300°F) for high-temperature variants. Interchangeability tolerances at 0 to 70°C are available in ±0.1°C or ±0.2°C.

Response time performance is specified as a 63% response of 1 second for bare elements in stirred oil bath, and up to 2.5 seconds maximum when PFA encased in air. For best stability, the recommended storage temperature range is -80 to 120°C (-110 to 250°F) for ±0.2°C models and -80 to 75°C (-110 to 165°F) for ±0.1°C models.

Typical Thermometric Drift

The series documentation provides typical drift values over time intervals of 10 months and 100 months:

• At 0°C: <0.01°C (both intervals)
• At 25°C: <0.01°C at 10 months, 0.02°C at 100 months
• At 100°C: 0.20°C at 10 months, 0.32°C at 100 months
• At 150°C: 1.5°C at 10 months; operation is not recommended for the 100-month interval.

Configuration Options

The series offers ten distinct model configurations based on resistance at 25°C, interchangeability tolerance, and maximum working temperature. Resistance values at 25°C include 2252 Ω, 3000 Ω, 5000 Ω, 10,000 Ω, and 30,000 Ω.

Physical Construction & Materials

• Bead Dimensions: 2.4 mm (0.095 in) diameter with an overall length of 76.2 mm (3 in).
• Wetted Materials: Epoxy coating on the bead; electrical connections use 32 AWG silver-plated copper or alloy 180 (copper/nickel) wire.

PFA Sleeving Options

An optional PFA sleeving configuration is available over one lead wire and as an overall jacket. To order this option, the middle digit of the model number changes to '1' (e.g., 44004 becomes 44104). This modification incurs additional cost.

Key Product Differences

The series distinguishes models by interchangeability tolerance and maximum working temperature:

• ±0.2°C Interchangeability (Models 44004, 44005, 44007, 44006, 44008): Maximum working temperature of 150°C (300°F).
• ±0.1°C Interchangeability (Models 44033, 44030, 44034, 44031, 44032): Maximum working temperature of 75°C (165°F).

Note that resistance tolerances vary based on the specific resistance at 25°C for each model. The series is RoHS compliant.