Introduction With the US Hot Cars Act requiring child presence detection in all new passenger vehicles by the 2028 model year, automotive-grade PIR sensors are becoming a critical component. This article covers the technical requirements and implementation considerations. Regulatory Context…

Introduction Pyroelectric sensors are widely used in flame detectors for industrial safety systems. Unlike motion detection, flame detection relies on sensing the characteristic flicker of flames and their spectral signature. Flame Characteristics Flames from hydrocarbon fires have two key properties…

Introduction While commonly used for motion detection, pyroelectric sensors are also the heart of Non-Dispersive Infrared (NDIR) gas sensors. This article explains the principles and applications. NDIR Principle NDIR gas sensing works on the principle that many gases absorb infrared…

Introduction PIR sensors are inherently sensitive to temperature because they detect thermal radiation. Ambient temperature changes can significantly affect performance, causing false triggers or missed detections. This guide covers compensation techniques. How Temperature Affects PIR Sensors Sensitivity Variation Pyroelectric materials…

Introduction While a single PIR sensor can detect motion, multiple sensors in an array can count people, determine direction, and even track movement. This guide covers array configurations and signal processing techniques. Why Use Arrays? People counting: Determine number of…

Introduction While many PIR applications work with default settings, precision applications require systematic calibration. This guide covers calibration procedures for optimal performance. Why Calibrate? Compensate for sensor-to-sensor variation Adapt to specific installation environment Optimize detection vs. false alarm trade-off Meet…

Introduction PIR sensors and modules offer different output interfaces. Choosing the right one and interfacing correctly is essential for reliable operation. Output Interface Types Push-Pull Digital Output Output is actively driven HIGH to VCC and LOW to GND. Can source…

Introduction PIR sensors are designed to detect human body radiation, which peaks around 9.7 μm. To achieve this selectively, they incorporate optical filters that transmit only the 8-14 μm band while blocking other wavelengths. Why Spectral Filtering Matters Without filtering,…

Introduction Noise is the enemy of reliable PIR detection. This guide identifies noise sources and provides practical mitigation strategies. Types of Noise in PIR Systems 1. Thermal Noise (Johnson-Nyquist) Fundamental noise from thermal agitation of charge carriers. Present in all…

Introduction PIR sensors do not respond instantly. Their response time is governed by two factors: the thermal time constant of the pyroelectric element and the electrical time constant of the readout circuit. This article explains these parameters and their practical…