Thermistor vs. PT100: What’s the Real Difference?
If you’re diving into the world of electronics or temperature control, you’ve probably hit a common question: What is the difference between a thermistor and a PT100? They both measure temperature, right? So why are there two different components doing the same job?
Well, it turns out they’re pretty different under the hood—and choosing the right one can make or break your project. Let’s break it down in plain English.
The Core Difference: How They Work
Think of it like this: a thermistor is a temperature-sensitive resistor, usually made from ceramic or polymer. Its resistance changes a lot with a small change in temperature. Most thermistors are called NTC types, meaning their resistance goes down as things get hotter.
A PT100, on the other hand, is a type of RTD (Resistance Temperature Detector). It’s made from pure platinum (hence the “PT”) and has a resistance of 100 ohms at 0°C. Its resistance changes in a much more linear and predictable way as temperature changes. It’s less sensitive but far more stable over a wide range.
Let’s Compare the Key Features:
| Feature | Thermistor 🚀 | PT100 (RTD) 🧊 |
|---|---|---|
| Accuracy | Great for small ranges | Excellent over a wide range |
| Temperature Range | Limited (usually -50°C to 150°C) | Very wide (-200°C to over 600°C) |
| Response Time | Fast | Slower |
| Cost | Low | Higher |
| Linearity | Non-linear (curve-shaped response) | Very linear |
Which One Should You Use?
You might prefer a Thermistor if:
You’re measuring a small temperature range (like in a 3D printer, coffee maker, or battery temp monitor).
You need a fast response.
Your budget is tight.
You should choose a PT100 if:
You need high accuracy over a wide temperature range.
Your project involves extreme temps (like industrial ovens, medical devices, or lab equipment).
Stability and repeatability are must-haves.
Wrapping It Up
So, the next time someone asks you, “What’s the difference between a thermistor and a PT100?”, you can tell them: thermistors are like sprinters—fast and sharp in a short race—while PT100s are like marathon runners—steady, reliable, and built for the long haul.
Your choice totally depends on your application. Hopefully, this guide helps you pick the perfect sensor for your next project!