Intrinsically Safe Dew Point Instrument For Hazardous Locations

Vaisala implements the DMP370 Intrinsically Safe Dew Point Instrument to provide continuous moisture measurement in hazardous industrial locations. The system integrates established sensor technology to support gas quality monitoring in hydrogen production, renewable gas infrastructure, and chemical processing facilities.

Addressing the Industrial Challenge
Moisture control is a critical parameter in gas processes, as excess moisture compromises fuel cell performance, reduces process efficiency, and shortens equipment lifetime in electrolyzers and industrial facilities. Measuring moisture in hazardous environments traditionally required operational compromises. Previous technologies necessitated additional protective enclosures, introduced installation constraints, or periodically interrupted measurement data during regeneration and heating cycles. Expanding hydrogen and biomethane applications require equipment specifically certified for explosive atmospheres to maintain operational reliability without data gaps.

Technical Solution and Responsibilities
The DMP370 system combines Vaisala's DMP37X probe and HMT370EX transmitter into a single intrinsically safe unit. The intrinsic safety design limits the electrical energy of the instrument, preventing it from functioning as an ignition source in explosive atmospheres. The architecture utilizes the proprietary DRYCAP dew point sensor integrated with a drift-compensation mechanism. The unit provides a measurement range of -70 to +10 degrees Celsius with a typical accuracy of plus or minus 2 degrees. Antti Heikkila, Product Line Manager of Industrial Decarbonization at Vaisala, stated that operators need measurement solutions that support both process performance and safety in hazardous locations, enabling continuous dew point measurement in applications where explosion safety is essential.

Deployment and Implementation
The instrument is certified for deployment in Zone 0 and 20 environments under ATEX and IECEx standards, and holds FM approval for Class I, II, and III, Division 1 classifications. The consolidated probe and transmitter configuration eliminates the requirement for heavy explosion-proof enclosures. The system delivers continuous measurement data without operational gaps, maintaining long-term stability and fast response times across pressure ranges up to 40 bar absolute and temperature profiles between -40 and +60 degrees Celsius. First deliveries of the calibrated hardware are scheduled for the first quarter of 2027.

Applications and Use Cases
The moisture measurement system is applied across diverse hazardous industrial environments to monitor gas purity and quality. Target applications include hydrogen storage and electrolyzer output monitoring, biogas upgrading for grid injection, and natural gas pipeline infrastructure. The technology is additionally utilized in chemical processing for synthetic fuels and methanol production, dry-process battery manufacturing where combustible carbon dust is present, and purge gas moisture monitoring.

Results and Expected Impact
Implementing the drift-compensated dew point instrument ensures continuous, uninterrupted gas-quality data acquisition in explosive atmospheres. The integration of intrinsic safety with continuous monitoring eliminates measurement blind spots caused by regeneration cycles. This technical stability allows operators to optimize fuel cell performance, mitigate operational risks in decarbonized gas applications, and maintain strict process efficiency without compromising the physical safety of the industrial infrastructure.

Edited by Maria Brueva, Induportals editor – adapted by AI.

www.vaisala.com