High-Humidity Sensors in Industry & Manufacturing

July 14, 2026

In our previous post, we described the challenges that high humidity, condensation, and harsh environmental conditions pose for sensors. However, even outside of high-humidity applications, there are numerous areas of use where sensors are constantly exposed to harsh conditions.

Especially in industrial and manufacturing environments, sensors must operate reliably over the long term under difficult conditions.

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In a nutshell

In industry and manufacturing, the focus is often not just on high humidity, but on the combination of moisture, dust, particles, aerosols, and air contaminated with chemicals. Over time, these factors can put a strain on sensors and impair measurement quality.

The AFTF-45 and KFTF-45 are designed for harsh environmental conditions and provide more stable long-term measurements in demanding production environments.

Typical benefits:

Consistent measurement results in contaminated industrial and production air
PTFE-protected sensors for harsh environments
Suitable for production facilities, technical areas, and air ducts
Support for Ventilation, Dehumidification, and Climate Control
Easy integration into building management systems, DDC, PLCs, or HVAC systems

Applications in Industry and Manufacturing Facilities

In industrial and manufacturing environments, challenging measurement conditions arise wherever production, airflow, heat, dust, or emissions converge. Sensors are not only exposed to humidity and temperature, but also frequently to particles, welding fumes, aerosols, or chemical compounds in the ambient air.

Typical applications include:

Production and Manufacturing Facilities
Welding shops and metalworking businesses
Areas with dust or air contaminated with particles
Engine and Machinery Rooms
Ventilation and exhaust ducts
Areas with varying production conditions

For operators, this means that humidity measurements must provide reliable readings even during continuous operation. This is the only way to reliably monitor and control ventilation, dehumidification, indoor climate, and system operation.

Why Traditional Humidity Sensors Reach Their Limits in Industrial Environments

Conventional humidity sensors are often designed for relatively clean indoor air. In industrial applications, however, the sensor element is exposed to additional stresses. Dust, particles, welding fumes, aerosols, or chemical emissions can accumulate on surfaces and affect measurement accuracy over the long term.

This change often occurs gradually. Measurements respond more slowly, deviate more significantly, or can no longer be reliably reproduced. This is critical for control systems because ventilation, dehumidification, and process monitoring all rely on reliable humidity and temperature readings.

This is exactly where the AFTF-45 and KFTF-45 come into play. The protected sensor system reduces the direct impact of harsh ambient air on the sensor element, thereby ensuring more stable measurements over longer periods of time.

Typical challenges: dust, particles, and changing production conditions

The most demanding conditions in industry and manufacturing result from a combination of air pollution, temperature fluctuations, and dynamic plant operations.

Typical influencing factors include:

Welding fumes and aerosols: Fine particles from manufacturing processes can accumulate on surfaces.
Dust and Particles: Production dust, material abrasion, or process particles can cause long-term damage to the sensors.
Chemical Emissions: Depending on the process, substances may be released into the air that affect sensor surfaces.
Temperature Change: Machine operation, facility ventilation, and downtime affect humidity and temperature conditions.
Airflow: Supply and exhaust air, extraction, recirculation systems, and HVAC systems all affect the local humidity distribution.

Therefore, it is not only crucial to select a robust sensor, but also to choose the appropriate measurement location. Direct process exposure, heavily contaminated zones, or areas with poor flow should be avoided during the planning phase.

Which metrics are relevant in industry and manufacturing?

In industrial and manufacturing settings, humidity and temperature are key parameters for indoor climate, ventilation, and equipment monitoring. However, especially under changing production conditions, the interplay of these measured values is also crucial.

Key metrics include:

Relative humidity—a key control parameter for indoor air, ventilation, and dehumidification
Temperature – affects humidity behavior, indoor climate, and process environment
Dew Point – Helps Assess Condensation Risks
Absolute humidity – indicates the actual water content of the air
Mixing ratio – aids in assessing air exchange and dehumidification

The AFTF-45 and KFTF-45 measure humidity and temperature and can provide additional calculated parameters for building management systems (BMS), distributed control systems (DCS), programmable logic controllers (PLCs), or ventilation systems.

AFTF-45 or KFTF-45—which model is right for you?

For industrial and manufacturing applications, both surface-mounted sensors and duct sensors may be suitable, depending on the system. The key factor is where the measured value is needed for control or monitoring.

AFTF-45 as a surface-mounted sensor

Wall mounting in production, technical, or industrial areas
Direct measurement of indoor air
Suitable for areas with contaminated ambient air

The AFTF-45 is suitable for measuring humidity and temperature directly in a room—for example, in production halls, machine areas, utility rooms, or adjacent areas.

KFTF-45 as a duct sensor

Installation in ventilation and exhaust ducts
Measurements in Supply or Exhaust Air Ducts
Suitable for HVAC systems, exhaust systems, recirculation systems, and central air distribution systems

The KFTF-45 is useful when humidity and temperature need to be measured in the air ductwork, such as for monitoring exhaust air, supply air, dehumidification, or central air conditioning.

In larger industrial facilities, a combination of the two may be useful: The room sensor monitors conditions in the production area, while the duct sensor monitors which air is being exhausted, treated, or recirculated.

Differences: AFTF-35 vs. AFTF-45

The AFTF-35 and KFTF-35 are the right choice when high humidity, humidity fluctuations, and the risk of condensation are key considerations.

AFTF-45 and KFTF-45 are useful when additional chemical or particulate contamination is present—for example, from dust, welding fumes, aerosols, emissions, or contaminated production air.

As a simple guide to help you decide:

Condensation and rapid changes in humidity are the main problem: Series 35
Dust, particles, aerosols, or contaminated air are the main problem: Series 45

Important: Even protected sensors are no substitute for proper planning of the measurement site. Direct exposure to process fluids, heavy contamination, or prolonged contact with liquids should be avoided.

Click here for our blog post on high-humidity applications (AFTF-35 / KFTF-35)

Select the right humidity sensors for industry and manufacturing now

In industrial and manufacturing environments, dust, particles, welding fumes, aerosols, chemical emissions, and fluctuating production conditions place special demands on sensor technology. The AFTF-45 and KFTF-45 are designed for harsh environmental conditions and ensure stable humidity and temperature measurements in contaminated ambient air.

For you, this means:

More reliable measurements in demanding industrial environments
A better foundation for ventilation, dehumidification, and system monitoring
less maintenance and replacement work
Easy integration into building management systems, DDC, PLCs, or HVAC systems
Suitable designs for in-room and duct measurements

Depending on the installation situation, choose the appropriate model: AFTF-45 for direct indoor air measurement or KFTF-45 for installation in supply and exhaust air ducts.

Discover Humidity Sensors for Industry & Manufacturing