Building on a Legacy of PID Development

Introduction

Photoionisation detection (PID) technology was born from urgent necessity in the early 1970s when vinyl chloride was identified as a carcinogen, forcing exposure limits to plummet from 500 ppm to just 1 ppm.

Existing flame ionisation detectors (FIDs) couldn’t reliably distinguish vinyl chloride from methane and acetylene, creating a critical safety gap that PIDs uniquely solved.

This application article traces PID’s remarkable journey from the first HNU PI101 handheld detector in 1974 through decades of innovation including response factor development, variable energy lamps, microprocessor integration for data logging and TWA/STEL calculations, and ION SENSE^®‘s groundbreaking Fence Electrode Technology and Anti-Contamination Technology.

Today’s PIDs represent the culmination of 50 years of refinement, delivering reliable VOC detection from parts per billion to 20,000 ppm under challenging field conditions, a testament to continuous innovation driven by increasingly stringent industrial hygiene requirements and the ongoing commitment to worker safety.