High-humidity sensors in the food industry and hygiene-sensitive areas

July 14, 2026

High humidity poses unique challenges for the sensors used in many applications. In our previous article, we already explained the challenges that arise from condensation, temperature fluctuations, and persistently humid environments.

But how do sensors perform under real-world conditions in hygiene-critical production areas?

Demanding environmental conditions are particularly common in the food industry and in hygiene-critical areas. Regular cleaning and disinfection processes, aggressive cleaning agents, and fluctuating operating conditions mean that sensors are not only constantly exposed to high humidity but also to chemical stress.

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In a nutshell

Food production and hygiene areas present unique challenges for humidity measurement. In addition to high humidity, sensor technology is often affected by spray mist, cleaning residues, aerosols, and particles. These factors can distort measurement readings, alter response times, or increase maintenance requirements.

The AFTF-45 and KFTF-45 are designed for harsh environmental conditions and provide more stable long-term measurements in polluted ambient air.

Typical benefits:

Stable readings despite humidity, cleaning agents, and contaminated air
PTFE-protected sensors for harsh environments
Suitable for production facilities, hygiene areas, and air ducts
Support for Ventilation, Cooling, and Dehumidification
Easy integration into building management systems, DDC, PLCs, or HVAC systems

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Use in food production and hygiene areas

In the food industry, challenging measurement conditions arise wherever production, cleaning, rinsing, filling, or packaging takes place. Sensors are not only exposed to high humidity, but often also to spray mist, cleaning residues, aerosols, and fine particles from the ambient air.

Typical applications include:

Production facilities with high ambient humidity
Filling and Packaging Areas
Sanitary areas that are cleaned regularly
Cleaning and Rinsing Areas
Utility and auxiliary rooms with contaminated ambient air
Supply and exhaust air ducts for HVAC systems

For operators, this means that humidity measurements must provide reliable readings even after cleaning cycles and under varying operating conditions. This is the only way to reliably control ventilation, cooling, and dehumidification and ensure stable production conditions.

Why Traditional Humidity Sensors Reach Their Limits in Hygienic Areas

Conventional humidity sensors are often designed for normal room air. In hygiene-critical production areas, however, the sensor element is exposed to additional stresses. Cleaning processes, moist aerosols, particles, and chemical residues can settle on surfaces and affect measurement quality over the long term.

The change is often not immediately apparent. In practice, the effects tend to be gradual: measured values respond more slowly, deviate more significantly, or take longer to stabilize after cleaning phases. This poses a problem for control systems because ventilation, cooling, and dehumidification 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: Cleaning, aerosols, and contaminated ambient air

In the food industry, the most demanding conditions often arise not during steady-state production, but during cleaning cycles, product changeovers, or when room conditions change.

Typical influencing factors include:

Cleaning Processes: Wet cleaning, disinfection, or rinsing processes can cause moisture spikes and leave residues.
Spray mist and aerosols: Fine droplets can settle on surfaces and affect measurement conditions.
Particulate Matter Pollution: Dust, product particles, or residues from the ambient air can contaminate sensor surfaces.
Temperature Change: Alternating between production, cleaning, and downtime changes humidity and temperature conditions.
Airflow: Supply and exhaust air, recirculation systems, and dehumidification affect the local humidity distribution.

Therefore, it is not only crucial to select a robust sensor, but also to choose the right measurement location. Direct spray mist, high local humidity spikes, or areas with poor airflow should be avoided during the planning phase.

What metrics are relevant in food and hygiene areas?

Humidity and temperature are the most important basic parameters for climate control in production and hygiene areas. However, the interaction of these measured values is also crucial, particularly during cleaning, cooling, or dehumidification.

Key metrics include:

Relative humidity—a key control variable for indoor air and dehumidification
Temperature – affects humidity behavior, condensation, and the process environment
Dew Point – Helps Assess Condensation Risks
Absolute humidity – indicates the actual water content of the air
Mixing Ratio – Helps Evaluate Ventilation and Dehumidification Processes

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 the food industry and hygiene-sensitive areas, 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, hygiene, or technical areas
Direct measurement of indoor air
Suitable for areas with humid and contaminated ambient air

The AFTF-45 is suitable for situations where humidity and temperature need to be measured directly in the room—for example, in production rooms, filling areas, packaging zones, or adjacent technical areas.

KFTF-45 as a duct sensor

Installation in ventilation and air conditioning ducts
Measurements in Supply or Exhaust Air Ducts
Suitable for HVAC systems, recirculating air systems, and central dehumidification

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

In larger systems, 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 primary concerns.

AFTF-45 and KFTF-45 are useful when additional chemical or particulate contamination is present—for example, from cleaning residues, spray mist, aerosols, or contaminated ambient air.

As a simple guide to help you decide:

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

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

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

Select the right humidity sensors for the food industry and hygiene-sensitive areas now

In food production and hygiene-sensitive areas, high humidity, cleaning processes, spray mist, aerosols, and fluctuating operating 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 production environments
a better foundation for ventilation, cooling, and dehumidification
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 ventilation and HVAC ducts.

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