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10. March 2022

Digital Immersion Probe for Determining Moisture in Oil

The MOP301 immersion probe by E+E Elektronik precisely measures the moisture in transformer, lubrication or hydraulic oils as well as diesel fuel. It is used for preventive maintenance of equipment and machinery. The stainless steel probe can be used in oils up to 120 °C (248 °F) and 20 bar pressure. The measured data for water activity, temperature and absolute water content are available via the RS485 interface with Modbus RTU protocol.

Excellent measuring performance, rugged design

The E+E humidity sensing elements used in the MOP301 are characterised by their long-term stability and resistance to contamination. They form the basis for high-precision and reliable humidity and temperature measurement. 

The immersion probe is impressive mechanically with a rugged stainless steel enclosure with protection class IP66, an oil-resistant cable and a moulded M12 connector. It can be used in a temperature range of -40 to 120 °C (-40...248 °F) and at up to 20 bar pressure. 

Various probe and cable lengths and the lean design enable particularly flexible installation of the MOP301. Thanks to the practical slide fitting, the immersion depth can be precisely set, and changed if needed. Using an optional ball valve, the probe can be installed and removed without interrupting the process and under pressure. 

Measured values an interfaces 

The MOP301 delivers the oil moisture content as an absolute or relative value. The water activity (aw) states the relative moisture content of an oil and describes the relationship between the actual and maximum possible amount of dissolved water. The aw value reveals how close the oil is to the saturation point at a specific temperature. 

The water content (x) expresses the moisture content in absolute figures. It is stated in ppm or mg water / kg oil. The MOP301 calculates the water content based on the measured water activity and temperature. The oil-specific parameters required for calculation can be factory pre-configured, written via Modbus RTU, or set retroactively with the aid of the PCS10 Product Configuration Software.

The measured values are provided via the RS485 interface using the Modbus RTU protocol.

Extensible to a sensor unit

The MOP301 is compatible with the Sigma 05 sensor hub by E+E Elektronik. The probe can be plugged into the host device based on the plug-and-play principle and thus extended to a sensor unit with analogue outputs and an optional display.

Downloads for this Information

DE Digitaler Eintauchfühler zur Bestimmung der Ölfeuchte
EN Digital Immersion Probe for Determining Moisture in Oil