On-wall humidity and temperature sensor AFTF-35
temperature Temperature
temperature Luftfeuchtigkeit

On-wall humidity and temperature sensor HYGRASGARD® AFTF-35

Product group: WG02

Low availability.

Usually ships in 3 to 5 days
738,13 €
878,37 € incl. VAT + shipping


On-wall humidity and temperature sensor HYGRASGARD® AFTF-35
Condensation-protected on-wall sensor HYGRASREG® AFTF-35 with active and switching output, housing made of impact-resistant plastic with quick-locking screws, cable gland, plastic sinter filter (replaceable), optionally with/ without display, for detecting relative humidity (0…100 % RH) and temperature (4 switchable measuring ranges, max. 0...+100 °C) as well as for determining various parameters of humidity measurement technology. The measuring transducer converts the measured variables into a standard signal of 0 - 10 V or 4…20 mA.
The unit is specially designed for use in the high humidity range (95…99 % RH). A long-term stable, digital humidity and temperature sensor is used. Overtemperature prevents or hinders dew formation on the humidity sensor. A second, separate temperature measuring element is used to determine the actual relative humidity of the ambient air. The following measured variables are calculated internally from these parameters and are retrievable via output OUT3: absolute humidity, mixing ratio, dew point and wet bulb temperature (can be changed via DIP switch).
The sensor is used in medical technology, refrigeration technology, control technology, air conditioning and clean room technology. The sensor is factory-calibrated; an environmental precision adjustment by an expert is possible.

Technical details

Voltage supply
24 V AC/ DC (± 10 %)
Power consumption
typically < 6 W at 24 V DC, peak current 200 mA
Data points
Temperature [°C], relative humidity [% RH], absolute humidity [g / m3],
dew point [°C], mixing ratio [g / kg], wet bulb temperature [°C]
Working resistance
> 100 kOhm for U -variant; 100...500 Ohm for I -variant
Measuring range, humidity
0...100 % r. H.
Deviation of humidity
typically ± 3.0 % (30...70 % RH) at +25 °C, otherwise ± 3.5 %. (Deviation of the alternative characteristic values result from the deviations of humidity and temperature).
Measuring range, temperature
Multirange switching with 4 switchable measuring ranges (see table) 0...+50 °C (default); -20...+50 °C; -20...+80 °C; 0...+100 °C
Temperature deviation
typically ± 0.5 K at +25 °C
Warm up time
< 10 min
Response time
< 60 s
digital humidity sensor
with integrated temperature sensor,
low hysteresis, high long-term stability
with condensation protection by heating function (plus a second, separate temperature measuring element)
Sensor protection
plastic sinter filter, Ø 16 mm, L = 35 mm, exchangeable
(optional metal sinter filter, Ø 16 mm, L = 32 mm)
Measuring ranges
0...+50 / –20...+50 / –20...+80 / 0...+100 °C
0...100 % RH
Ambient temperature
storage –20...+50 °C; operation –20...+50 °C
Process connection
By means of screws
Protective tube
made of stainless steel V2A (1.4301), Ø 16 mm, NL = 55 mm (combined humidity and temperature measuring element) and of stainless steel V4A (1.4571), Ø 6 mm, NL = 65 mm (via a second, separate temperature measuring element)
Electrical connection
3- or 4-wire connection
0.14 - 1.5 mm² via plug terminals
plastic, UV-stabilised,
material polyamide, 30 % glass-globe reinforced,
with quick-locking screws
(slotted/ Phillips head - combination),
colour traffic white (similar to RAL 9016),
housing cover for display is transparent !
Cable gland
M 16 x 1.5, including strain relief, exchangeable,
max. inner diameter 10.4 mm
126 x 90 x 50 mm (Tyr 2)
vertical mounting, humidity sensor at the bottom
Long-term stability
± 1 % per year
Permissible air humidity
< 99% r.H. pollutant-free, non-precipitating air
Protection class
III (according to EN 60 730)
Protection type
IP 65 (according to EN 60 529) in the built-in state,
Housing tested, TÜV SÜD, Report No. 713139052 (Tyr 1)
Protection type housing
IP 65
Due to a constant overtemperature of the humidity sensor, its dewing is significantly impeded or prevented within the system limits.
A faster reaction speed to humidity fluctuations is achieved, even in the range above in the range above 95 % RH. The sensor (combined humidity and temperature measuring element) is heated approx. 3 K above the ambient temperature. From the measured relative humidity at overtemperature, the chip temperature of the sensor and the ambient temperature (via a second, separate temperature measuring element) the actual relative humidity is determined.