100K NTC N3950 Glass Shell Thermistors MF58

100K NTC Thermistor (MF58 Glass Shell, B3950) is a high-precision, negative temperature coefficient (NTC) temperature sensor encased in a rugged glass shell, making it ideal for accurate temperature measurement in harsh or humid environments. This specific model features a resistance of 100kΩ at 25°C and a critical B-value of 3950K, ensuring exceptional sensitivity and stability across a wide operating range. Engineers choose the MF58 series for its long-term reliability and chemical resistance, enabling its use in demanding applications where smaller, more delicate sensors might fail.

Key Features:

• High Thermal Stability: The robust glass-sealed body protects the thermistor element from moisture, gases, and other contaminants, providing excellent long-term stability and reliability.
• High Sensitivity (B3950): This specific B-value ensures a steep resistance-to-temperature characteristic, which delivers high thermal resolution for precise temperature detection.
• Wide Temperature Range: Capable of operating effectively from −55°C up to +200°C, these thermistors meet the stringent requirements of both commercial and industrial applications.
• Fast Response Time: The small size and minimal thermal mass of the glass shell allow the thermistor to quickly respond to temperature changes.
• Standard R₂₅ Value: The 100kΩ nominal resistance at 25°C is a common industry standard, simplifying integration with standard microcontroller ADC circuits.

Technical Specifications:

• Zero Power Resistance (R₂₅): 100 kΩ ±1% (at 25°C)
• B-Value (B_25/50): 3950 K ±1% (Calculated from 25°C to 50°C)
• Thermal Time Constant: τ ≤ 10 seconds (In air)
• Dissipation Factor (δ): ≈ 2.5 mW/°C (In still air)
• Maximum Rated Power: 50 mW
• Operating Temperature Range: −55°C to +200°C

Mechanical Specifications:

• Encapsulation: Hermetically Sealed Glass Shell (MF58 Series)
• Lead Material: Tinned Copper Alloy
• Lead Style: Axial Leads
• Insulation Resistance: ≥ 100 MΩ (Ensures accurate reading even in high humidity)

Dimensions:

• Glass Body Diameter (D): ≈ 1.8 mm
• Glass Body Length (L): ≈ 3.5 mm
• Lead Wire Diameter: ≈ 0.3 mm
• Overall Length (L_total): ≈ 60 mm (Typically 30 mm leads on each side)
• Weight: ≈ 0.1 g (Extremely lightweight sensor)

Pinout and Wiring:

• Pin 1 / Lead 1: Connect to the voltage supply (V_CC) through a stable series resistor (R_series) to form a voltage divider circuit.
• Pin 2 / Lead 2: Connect to the ADC input pin of your microcontroller (MCU) and to Ground (GND) to complete the voltage divider circuit.
• Wiring Note: Since thermistors are non-polarized resistors, the leads are interchangeable, but you must measure the voltage across the thermistor (or the series resistor) to determine temperature. Use a stable R_series that is close to the R₂₅ value (100kΩ) for best resolution around room temperature.

Datasheet Reference:

• Download MF58 NTC Thermistor Datasheet (Fenghua)

Commonly Used in:

• 3D Printers: Monitoring the temperature of hot ends and heated beds where high temperatures and precision are crucial.
• Automotive Electronics: Measuring engine coolant, air intake, or cabin temperatures due to its wide range and ruggedness.
• HVAC and Refrigeration: High-accuracy temperature control in air conditioning, freezers, and industrial cooling systems.

Applications:

• Temperature Compensation: Used in electronic circuits to balance the temperature-dependent drift of other components like op-amps or crystal oscillators.
• Fluid Temperature Sensing: The glass shell makes it excellent for submersion in non-corrosive liquids for fluid temperature monitoring.
• High-Accuracy Digital Thermometry: Implementing precise temperature feedback loops in scientific and industrial instruments.

Equivalent Models:

• B57301K0104J050 (EPCOS/TDK): A 100kΩ, B3950 equivalent model with similar glass encapsulation.
• NCP18WB104J03RB (Murata): A commonly referenced NTC thermistor with a 100kΩ R₂₅ and similar B-value, though often in an SMD package.
• NTCS0805E4104JXT (Vishay): A glass-encapsulated NTC with matching 100kΩ/3950K specs, suitable for direct substitution.

Package Includes:

• 1 x 100K NTC Thermistor (MF58 Series, B3950)