Hand-Held Humidity and Temperature Meter HM40
Compact, portable, and easy to use, the Vaisala HUMICAP® HM40 series handheld humidity and temperature meters are designed for reliable spot-checking across a wide range of environments. They are ideal for applications ranging from structural moisture assessment and air conditioning systems to humidity measurements in industrial production processes and life science environments. Four configurations are available to meet different measurement needs:
- HM41 – General-purpose handheld meter for everyday spot checks across HVAC, structural moisture, industrial, and life science applications.
- HM42 – Handheld meter with a thin 4 mm stainless steel probe for measurements in tight spaces such as seams, joints, and beneath flooring.
- HM45 – Robust handheld meter for demanding spot checks in HVAC, industrial production, and life science environments.
- HM46 – Handheld meter with a long stainless steel probe for measurements in hard-to-reach locations such as ducts or high-temperature areas.
Key features
- Compact, portable, and easy to use with an intuitive user interface available in 10 languages
- Accuracy on par with Vaisala’s high-end measurement solutions
- Measures multiple humidity and temperature parameters
- Numerical, statistical, and graphical trend views to track changes and confirm measurement stability
- Delivered with a calibration certificate; probes are removable and interchangeable
Trust every spot check with a calibrated reference
A handheld device calibrated on time and traceable to a trusted provider like Vaisala serves as a reliable reference point for spot-check measurements. Vaisala’s devices always come with a calibration certificate, confirming that the sensor has been tested against known reference standards and that its measurement errors are within acceptable limits—ensuring the instrument performs as specified and delivers dependable results.
Vaisala’s calibration laboratories are accredited according to ISO/IEC 17025 by the world’s leading accreditation authorities, ensuring traceability to international measurement standards and certified compliance. For users in HVAC, industrial production, and life science environments, this means confidence in every spot check, reduced risk of incorrect decisions, and clear insight into measurement uncertainty—so results can be trusted in both routine checks and critical applications.
HM40 series in various applications
HM40 in art preservation and conservation
Preserving valuable artworks requires precise control of environmental conditions. The Vaisala HM40 Handheld humidity and temperature meter supports art conservators and museum professionals by providing fast, reliable, and highly accurate humidity and temperature measurements in galleries, storage areas, and during restoration work.
Accurate humidity control is critical, as even small variations can cause canvas deformation, paint flaking, or long-term material degradation. The HM40 enables conservators to verify that strict environmental requirements—often specified in international loan agreements—are met and maintained. During delicate restoration processes, such as controlled humidification of canvases, the HM40 provides dependable measurement data that helps professionals make informed decisions while protecting the artwork’s originality and integrity for future generations.
HM40 in HVAC and indoor air quality applications
Maintaining optimal indoor air quality is essential for occupant comfort, health, and energy efficiency in commercial and public buildings. The Vaisala HM40 Handheld humidity and temperature meter is used by HVAC professionals, facility managers, and commissioning engineers to quickly and accurately verify humidity and temperature conditions in shopping malls, office buildings, hospitals, and other critical indoor environments.
Accurate humidity control plays a key role in preventing issues such as condensation, mold growth, static electricity, and discomfort caused by overly dry or humid air. The HM40 enables reliable spot checks and system verification during installation, commissioning, and maintenance of HVAC systems. Its fast response time and high measurement accuracy make it an ideal reference instrument for validating building automation sensors and ensuring that indoor climate conditions meet regulatory requirements, design specifications, and comfort standards.
By providing dependable, portable measurements, the HM40 helps ensure healthy indoor environments, supports efficient HVAC operation, and contributes to long-term building performance.
HM40 in construction applications
Controlling humidity is critical throughout construction and finishing phases to ensure quality, durability, and healthy indoor conditions. The V Vaisala HM40 Handheld humidity and temperature meter is used by construction professionals, site managers, and inspectors to accurately verify humidity and temperature levels in buildings under construction, renovation sites, and finished premises.
Excessive humidity can significantly delay paint and coating drying times, compromise surface quality, and increase rework costs. In concrete structures, elevated moisture levels can prevent proper curing and create conditions that promote mold growth, potentially leading to long-term structural and indoor air quality issues. The HM40 enables fast and reliable spot checks to confirm that environmental conditions are suitable for painting, flooring installation, and other moisture-sensitive construction activities.
With its high accuracy and portability, the HM40 supports on-site decision-making, helps prevent moisture-related defects, and contributes to safer, higher-quality construction outcomes.
HM40 in storage applications
Proper humidity and temperature control are essential in storage environments to protect goods, materials, and equipment from damage. The Vaisala HM40 Handheld humidity and temperature meter is used by warehouse operators, facility managers, and quality personnel to accurately monitor environmental conditions in storage areas, cold rooms, and logistics facilities.
Excessive humidity can lead to mold growth, corrosion, packaging damage, and degradation of stored products, while overly dry conditions may cause material cracking, static electricity, or product quality issues. The HM40 enables fast and reliable spot checks to verify that storage conditions remain within specified limits and to identify potential risks before damage occurs.
With its high measurement accuracy and portable design, the HM40 supports quality assurance, helps protect stored assets, and ensures stable storage conditions across a wide range of industries.
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