LF-TD 90
humidity and temperature sensing device for industrial applications


Industrial measuring transducer for humidity and temperature

Moisture transmitter for temperatures of up to 90°C for laboratory, climate control and drying technology, wood processing industry, food and animal feed industry, building industry, printing and paper industry, agriculture, biotechnology and pharmaceutical industry.

article. no. 12665 LF-TD 90 humidity and temperature sensing device for industrial applications


In the manufacturing process, further processing, storage and transport, the exact determination of moisture and temperature becomes increasingly important. Only an accurate moisture monitoring can guarantee high product quality.

The LF-TD transmitters of Schaller measurement instrumentation, with its robust and easy to mount aluminium housing, are best suited for all applications in this field. A robust sensor tube of 125mm length (Ø 12mm) made of stainless steel with screwed sensor cap enlargens the application potential of the LF-TD 90 humidity and temperature transmitter. Diverse sensor caps (steel sinter, bronze sinter, plastic with or without filter, …) are available optionally.

As standard version, the moisture and temperature values are output via analogue 4-20mA power output. Alternatively, for the LF-TD 90 humidity and temperature transmitter also other interfaces like for example RS232, Profinet, Modbus or USB can be used.

The optionally available display showing the current moisture and temperature value is another add-on enlargening the application possibilities of the transmitter.

Two optional relay outputs enable the direct control of an alarm or air conditioning, for example. These switching outputs can be configurated freely directly at the LF-TD 90 humidity transducer (switch-points, hysteresis).

Thanks to the enclosed 1.9 meter connection cable with 5-pole moulded and robust sensor connector (on the sensor side), the sensor can be connected to existing plants without any difficulty. The other end of the cable is equipped with wire end ferrules for the easy connection to the control box or something similar.

The used capacitive moisture sensor ensures long-time stable and accurate measuring values and is resistant to normal pollution and a lot of chemicals. Furthermore, the sensors used in the LF-TD transmitters are characterised by rapid conditioning.  

The excellent measuring accuracy of the LF-TD series is guaranteed by a factory-calibration at six humidity points. On request a calibration certificate can be provided.

LF-TD 90 humidity and temperature sensing device for industrial applications

Technical drawing

Technical Drawing LF-TD 90 humidity and temperature sensing device for industrial applications

Technical data

type LF-TD90
article no. 12665
Measuring range  
Relative air humidity 0 to 100 %
Temperature -20°C to +90°C
Relative air humidity 4 - 20mA
Scaling air humidity 0 to 100 %
Temperature 4 - 20mA
Scaling temperature -20°C to +90°C
accuracy factory calibration    
Relative air humidity 10 to 90%:  ± 2,0 %
Temperature +10 to +60°C:  ± 0,3 °C
Operating temperature  
Sensor head -20°C to +90°C
electronics -20°C to +85°C
Power supply  
Voltage 24 VDC  (12 to 29VDC)
Current consumption approx. approx. 18 mA 1)
Dimensions and others:  
Dimensions sensor head Ø 12 x 125 mm
Material sensor head: stainless steel
Sensor cap: plastic with filter paper
dimensions electronics housing 70 x 32 x 120 mm
Material electronics housing anodised aluminium
protection class
electronics housing
IP 54
Electric connection sensor plug
display article no. 12662
relay output for moisture article no. 12806
RS232 interface article no. 12807
USB interface article no. 12808
Bluetooth (only with USB
interface article no. 12808)
article no. 12627
Profinet interface article no. 12809
Ethernet interface article no. 12810
Modbus interface article no. 12811
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