MF52-103 10K Ohm NTC Thermistor - 5% Tolerance Temperature Sensor

Specifications

• Model: MF52-103 / 3435

• Type: NTC (Negative Temperature Coefficient)

• Nominal Resistance (at 25°C): 10K Ohms (10,000Ω)

• Resistance Tolerance: ± 5%

• B-Constant (B25/50): 3435K

• Operating Temperature Range: -55°C to +125°C

• Coating: Black Epoxy Resin

Key Applications and Projects

• Digital Weather Stations: Wiring the thermistor to an ESP32 to track outdoor ambient temperature and display it on an OLED screen or web dashboard.

• 3D Printer Hotbeds: Taping the sensor to the underside of a heated aluminum build plate to provide precise temperature feedback to the motherboard.

• Automated PC Fan Controllers: Reading the temperature inside a computer case and using an Arduino to automatically increase the speed of PWM cooling fans as the case gets hotter.

Unlock New Capabilities (Project Evolution)

• The Smart Automated Fermentation Chamber: Brewing kombucha, beer, or making yogurt requires strict temperature control. Evolve your setup! Use a long wire to extend this 10K thermistor and waterproof the tip with heat shrink tubing and hot glue. Drop it into your fermentation vessel. Connect it to an Arduino that controls a heating pad via a relay. Write a simple sketch to turn the heater on if the temperature drops below 75°F, and off when it hits 80°F. You now have a flawless, automated climate control system for perfect brewing every time!

Package Includes:

• 1 x 10K 5% NTC Thermistor (MF52-103)

FREQUENTLY ASKED QUESTIONS (FAQ)

1. What does "NTC" stand for? NTC stands for Negative Temperature Coefficient. It means the electrical resistance goes down as the temperature goes up.

2. What does "10K" mean? It means the base resistance of the sensor is exactly 10,000 Ohms when the ambient temperature is 25°C (77°F).

3. Is this a digital or analog sensor? It is a purely analog sensor. It does not send digital data; it simply changes its physical resistance. You must use an Analog-to-Digital Converter (ADC) pin on your microcontroller to read it.

4. Does polarity matter? (+ and -) No. Like a standard resistor, a thermistor has no polarity. You can hook it up in either direction in your circuit.

5. How do I wire this to an Arduino? You cannot connect it directly to an analog pin. You must create a "Voltage Divider" circuit by connecting one leg of the thermistor to 5V, the other leg to an Analog pin (like A0), and then running a standard 10K resistor from that same Analog pin to Ground.

6. What is the maximum temperature it can read? The standard epoxy-coated MF52 thermistor is rated for temperatures up to 125°C (257°F).

7. Can I use this for my 3D printer's hotend? No. A 3D printer hotend routinely reaches 200°C to 250°C. The black epoxy coating on this sensor will burn and melt. You must use a glass-bead thermistor for hotends. This sensor is only safe for heated beds or ambient air.

8. Is it waterproof? The black epoxy head is moisture-resistant, but the bare metal legs will short out if submerged in water. If you want to drop it in liquid, you must cover the legs tightly with heat shrink tubing and marine-grade sealant.

9. What does the "5%" tolerance mean? It means the actual resistance at 25°C might vary by up to 5% from exactly 10,000 Ohms (between 9,500 and 10,500 Ohms). This translates to a slight temperature reading variance of a degree or two out of the box.

10. How do I make the reading more accurate? You can calibrate it! Dip the waterproofed sensor in ice water (0°C) and then boiling water (100°C), and adjust the math in your Arduino code to compensate for the 5% manufacturing tolerance.

11. What is the "3435" number? That is the B-Value (Beta Constant). It is a number used in the Steinhart-Hart equation within your code to accurately calculate the temperature curve.

12. Can I extend the wires? Yes, you can solder much longer wires to the two metal legs. Because 10,000 Ohms is a relatively high resistance, adding a few feet of copper wire will not noticeably affect the temperature reading.

13. Why is my Arduino reading fluctuating wildly? This usually happens if your voltage divider is set up incorrectly, if you used a resistor other than 10K, or if your wires are loose in the breadboard.

14. Can I use this with a Raspberry Pi? The Raspberry Pi does not have built-in Analog (ADC) pins. To read this analog thermistor on a Pi, you must add an external ADC chip (like an MCP3008) via I2C or SPI.

15. How fast does it react to temperature changes? Because the black epoxy "pearl" is so tiny, it has a very low thermal mass. It reacts to temperature changes in just a few seconds.

16. Can I attach this directly to a metal surface? Yes, you can tape it to a metal surface using Kapton tape. For the most accurate reading, put a tiny dab of thermal paste between the black sensor head and the metal surface.

17. What happens if I accidentally send 5V directly through it without a resistor? If you connect one leg directly to 5V and the other directly to Ground, it will create a short circuit as the temperature rises, rapidly overheating and permanently destroying the sensor. Always use a voltage divider.

18. Is this a PT100 sensor? No, a PT100 is an RTD (Resistance Temperature Detector) made of platinum, which is much more expensive and requires a complex amplifier board. This is a simple NTC thermistor.

19. How do I test if it's broken? Set a multimeter to the Resistance (Ohms / Ω) setting, specifically the 20K range. Touch the probes to the two metal legs. At room temperature, it should read roughly 10.00. Pinch the black head between your warm fingers, and the number should rapidly drop.

20. Can I cut the metal legs shorter? Yes, you can snip the metal legs to whatever length fits your project, just be sure to leave enough room to solder or crimp your connections.