Application Note The Importance of Trace Moisture Measurement in Compressed Air Systems Moisture is one of the most persistent and costly contaminants in compressed air systems. Even after filtering and compressing air, water vapour remains present and can condense at any point where temperature or pressure changes. Dewpoint measurement is the most reliable way to understand, control and prevent moisture related problems in compressed air networks. Compressed air systems are vital in many industries, powering tools, automation and processes. Dewpoint measurement within these systems is critical to ensure efficiency, reliability and product quality. Dewpoint in compressed air The dewpoint is the temperature at which water vapour in the air begins to condense into liquid at a given pressure. In compressed air systems, this is often expressed as pressure dewpoint (PDP), which accounts for the elevated pressure inside pipes and equipment. High dewpoint → more moisture present Low dewpoint → drier air When compressed air enters cooler environments, air with a high dewpoint is highly likely to produce liquid water downstream. Compressed air systems Often referred to as the “fourth utility”, a compressed air system is a setup that captures atmospheric air, compresses it to a higher pressure and distributes it for use as a power source, process medium or control mechanism in industrial and commercial applications. Compressed air systems generate, store and distribute air under pressure for various applications, including: Manufacturing: Operating pneumatic tools, actuators and controls. Food and Beverage: Packaging, conveying and cleaning. Pharmaceuticals: Instrumentation and process control. Automotive: Spray painting, tyre inflation and assembly lines. These systems typically consist of compressors, air receivers, dryers, filters and distribution pipework. Problems caused by trace moisture in compressed air systems Unchecked moisture can cause serious problems with the compressed air system performance, such as: Equipment damage and corrosion Water promotes rust in steel pipes, valves, actuators and air tools. Over time, this causes leaks and pressure losses, increased maintenance costs and premature equipment failure. In extreme cases, corrosion flakes can travel downstream and damage sensitive components. Product quality issues In industries such as food and beverage, pharmaceuticals, electronics and automotive painting, moisture contamination can spoil products, cause surface defects (e.g. paint fisheyes) and compromise hygiene and sterility. For these sectors, monitoring and controlling dew point is not optional - it is a qua

Application NoteThe Importance of Trace Moisture Measurement in Compressed Air Systems Freezing risks in cold environments When possible, avoid exposing compressed air to temperatures below freezing, as moisture within the air will form ice. This can lock airlines, jam valves and actuators and completely shut down production. Monitoring dew point helps ensure it always stays safely below the lowest ambient temperature. Dewpoint and dryer performance Different types of air dryers are designed to achieve specific dew point levels: Suitable Products A malfunctioning dryer may still appear operational...