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KT-300 Moisture in Oil Sensor

KT-300 is a fast, reliable and accurate online detector for water activity (aw) in oil and temperature (T). It is very suitable for integration in OEM application with its rugged housing and excellent performance.

KT-300 is ideal for online monitoring of moisture in lubrication, hydraulic or insulation oil, which is significant for the long-term performance and preventive maintenance of plant and machinery.



  • Continuous measurement of water activity in oil and temperature
  • Professional calculation of moisture content in ppm for transformer oil
  • Accurate and reliable, robust design under hostile environments
  • Convenient local & remote calibration
  • Excellent pollution & pressure tolerance
  • Compact, easy for integration
  • Analog and Digital Signals Output
Water activity  
Measurement range0 … 1 aw
Accuracy0 … 0.6:  ± 0.02 aw
0.6 … 0.9: ± 0.03 aw
 0.9…1: ±0.04 aw
Resolution 0.001 aw
Response time (typical)< 1 min
Water in oil 
Measurement range 0…100ppm, 500ppm, 1000ppm, 2000ppm or customized 
Accuracy ±10% or 10ppm (choose the higher one)
Measurement range -40 … 120 °C
Accuracy (at +25 °C)± 0.2 °C
Working temperature-40 … +80 °C
Storage temperature-40 … +80 °C
Oil temperature permitted -40 … +120 °C
Digital signal RS485 MODBUS RTU
Analog signal 4~20mA, resistive load 500Ω 
Housing material 316 stainless steel
Weight200g (transmitter), 270g(package)
Package size172×117×53 mm carton 
Ingress Protection IP66
Mechanical connectionsG 1/2″ ISO or 1/2″ NPT
Pressure range Max 100 bar (confirm with Kongter for other ranges)
Resistance load 200 … 500 Ω
Supply voltageDC 9V-36V(RS485 communication), DC15V-36V(@4-20mA)
Supply current <5mA+load current
Cable specification M8*1, 6 pin
Cable length 2 m 
Standard appliedCE certified, EN61326-1,EN61000-3,EN61010 class B

Stainless steel filter
USB-RS485 converter
USB-RS232 converter
Seal washer: ISO G1/2”
Connecting cable: 5m, M8 screw thread, 90°bend angle
                10m, M8 screw thread, 90°bend angle
2m, M8 screw thread, with LED light
Display and control unit: KT-200D (optional)

KT-300 Moisture in Oil and Temperature Transmitter       
Measurement parameters  aw + TA      
ppm + T 1)B      
aw + ppm + T 1)C      
Signal output4-20mA + RS485   1    
0-20mA + RS485  2    
0-5V + RS485  3    
RS232  4    
Analog output channel 10 … 1 aw   D   
0 … 100 ppm    E   
0 … ___ ppm   F   
Analog output channel 2‐40 … 120°C    5  
___ … ___°C    6  
Mechanical connector1/2” NPT      H 
Cable length 2 meters      7
3 meters      8
  • ppm is only applicable to mineral transformer oil. If you need to measure ppm value in other oil, please contact us.

Example for order: KT-300 B1E5H7
Measurement parameters: ppm + T                 
Signal output: 4‐20mA + RS485 
Ppm range: 0 … 100 ppm 
Temperature range: ‐40 … 120°C
Mechanical connections: 1/2” NPT
Cable length: 2 meters

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