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Your advantages

User-friendly handling
when recognising and reading the oil temperature and remaining oil life.

Reliable warning messages
when predefined limit values are exceeded, e.g. max. oil temperature.

Individually plannable maintenance intervals
ensure optimum utilisation of the oil service life and reduce maintenance costs.

The remaining oil service life always in view

The DUO (Diagnostic Unit Oil Aging) diagnostic unit performs transmission oil diagnostics by means of thermal analysis. A thermal sensor measures the oil temperature and transmits it to the evaluation unit, which uses it to calculate the remaining service life for the set oil type.

All you have to do is set the predefined limit values so that the DUO sends you appropriate warning messages if they are exceeded. In practice, this means that you can keep an eye on the remaining oil service life and therefore the performance of your mechanical drive technology at all times.

Diagnostic units are the perfect complement to our gear units, helping you to monitor the residual oil service life during operation, carry out diagnostics and optimize maintenance intervals.
All these facts make diagnostic units an important part of any condition monitoring concept.
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  • Perfect sensor technology for determining the remaining service life of the transmission oil and reliably displaying the time for an oil change
  • A thermal sensor installed in the gear unit measures the oil temperature and forwards this information to an evaluation unit, which uses it to calculate the remaining service life for the set oil type
  • The diagnostic unit takes into account the oxidation behaviour of the various oils under temperature load
TD Value
Oil types
  • Mineral oil CLP or bio-oil
  • Tmax = 100°C
  • Synthetic oil CLP HC or CLP PAO
  • Tmax = 130°C
  • Polyglycol CLP PG
  • Tmax = 130°C
  • Food grade oil
  • Tmax = 100°C
Approved oil temperature -40...+130°C
Approved temperature sensors Pt100 or Pt1000
EMC EN61000-4-2 electrostatic discharge: 4 kV CD / 8 kV AD
EN61000-4-3 HF radiated: 10 V/m
EN61000-4-4 Burst: 2 kV
EN61000-4-6 RF conducted: 10 V
Ambient temperature -20...+70°C
Operating voltage DC 18 ... 28 V1)
Current consumption at DC 24 V < 90 mA (with active display)
Protection class III
Degree of protection IP67 (optional IP69K)
Housing materials Diagnostic unit
 V2A; EPDM/X (Santoprene); PBT (Pocan); FPM (Viton)
Temperature sensor V4A
Electrical connection Diagnostic unit M12 plug-in connection
Temperature sensor
  • PT1000: M12 plug-in connection
  • PT100: Plug-in connection according to Deutsches Institut für Normung 43650
  • Helical gearboxes, sizes R67 - R167
  • Parallel shaft gearboxes, sizes F57 - F157
  • Bevel gearboxes, sizes K37 - K187
  • Worm gearboxes, sizes S67 - S97

For mounting on small sizes or industrial gear units, please contact SEW-EURODRIVE.

  • The DUO diagnostic unit is recommended for a wide range of industries and areas of application. Continuous monitoring of the remaining oil life allows the optimum oil change time to be determined.
  • It is particularly useful when loads, speeds and ambient temperatures vary. Under such conditions, it is difficult to determine the optimum oil change time using service life curves.
  • The risk of failure can also be reduced with the DUO diagnostic unit in critical systems with high follow-up costs due to machine / production downtimes.